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c语⾔程序设计第三版苏⼩红_C语⾔学习⽇志（三）参考资料：C语⾔程序设计（第三版）练习⽹站：PTA第三章：分⽀结构任何程序都可以使⽤三种基本的控制结构来实现，即顺序结构，分⽀结构和循环结构。
⼆分⽀结构与多分⽀结构（if型）例3-1//简单的猜数游戏3-2：//判断整数的奇偶性例3-3//输⼊⼀批学⽣的成绩，计算平均分，并统计不及格的学⽣⼈数例3-4//计算多分段函数以上是多种分⽀结构在实际程序中的使⽤。
字符型数据及其输⼊与输出3-5：//求解简单的四则运算表达式1:字符型常量每个字符都有唯⼀的次序之，即ASCII码2：字符型变量字符型变量在定义时⽤类型名char，例如:char = op;定义了⼀个字符型变量op，它的值是字符型数据。
op='+'将字符型常量‘+’赋给字符型变量op。
3：字符型数据的输⼊与输出字符型数据的输⼊输出可以调⽤函数scanf(),printf(),getchar(),putchar().注：在上述函数调⽤的过程中，格式控制字符串中相应的格式控制说明为%cgetchar()可以从键盘输⼊⼀个字符，putchar()可以从键盘输出⼀个字符逻辑运算C语⾔提供了三种逻辑运算符：单⽬：！ 逻辑⾮双⽬：&& 逻辑与 和 || 逻辑或！a：如果a为真，则结果为假；如果a为假，则结果为真。
a&&b：当a和b都为真时，结果为真；否则结果为假。
a||b：当a和b都为假时，结果为假；否则结果为真。
例3-6：//统计字符，包括英⽂字母，数字字符和其他字符switch语句3-8：//查询⾃动售货机中商品的价格switch语句可以处理多分⽀选择问题，根据其中break语句的使⽤⽅法，⼀般分为三种情况1：在switch语句的每个语句段中都使⽤break语句switch注：switch语句中的default可以省略，如果省略了default，当表达式的值与任何⼀个常量表达式的值都不相等时，就什么都不执⾏。
2.2 #include<stdio.h>main(){float x=2.5,y=2.5,z=2.5;printf("x=%f\n",x);printf("y=%f\n",y);printf("z=%f\n",z);}3.1(1)#include<stdio.h>main(){int a=12,b=3;float x=18.5,y=4.6;printf("%f\n",(float)(a*b)/2);printf("%d\n",(int)x%(int)y);}3.1(2)#include<stdio.h>main(){int x=32,y=81,p,q;p=x++;q=--y;printf("%d %d\n",p,q); printf("%d %d\n",x,y); }3.2#include<stdio.h>main(){int x,b0,b1,b2,s;printf("Inputx:");scanf("%d",&x);b2=x/100;b1=(x-b2*100)/10;//或(x%100)/10;或x/10%10;b0=x%10;s=b0*100+b1*10+b2;printf("s=%d\n",s);}3.3#include<stdio.h>#include<math.h>main(){float rate=0.0225;float n,capital,deposit;printf("Input n,capital:");scanf("%f,%f",&n,&capital);deposit=capital*pow(1+rate,n);printf("deposit=%f\n",deposit);}3.4#include<stdio.h>#include<math.h>main(){float a, b, c;double x, y;printf("Input a, b, c:");scanf("%f %f %f", &a, &b, &c);x=(-b+sqrt(b*b-4*a*c))/(2*a);y=(-b-sqrt(b*b-4*a*c))/(2*a);printf("x=%f,y=%f\n",x,y);}习题4 Array 4.1(1)#include<stdio.h>main(){char c1='a',c2='b',c3='c';printf("a%cb%cc%c\n",c1,c2,c3);}4.1(2)main(){int a=12,b=15;printf("a=%d%%,b=%d%%\n",a,b);}#include<stdio.h>main(){int a,b;printf("%d,%d\n",a,b);}4.2#include<stdio.h>main(){long a,b;float x,y;scanf("%d,%d\n",&a,&b);scanf("%f,%f\n",&x,&y);printf("a=%d,b=%d\n",a,b);printf("x=%f,b=%f\n",x,y); }5.1#include<stdio.h>main(){float a;printf("Input a:");scanf("%f",&a);if(a>=0){a=a;printf("a=%f\n",a);}else{a=-a;printf("a=%f\n",a);}}5.2#include<stdio.h>main(){int a;printf("Input a:");scanf("%d", &a);if(a%2==0)printf("a是偶数");}else{printf("a是奇数");}}5.3#include<stdio.h>#include<math.h>main(){float a,b,c,s,area;printf("Input a, b, c:");scanf("%f %f %f", &a, &b, &c);if(a+b>c&&a+c>b&&b+c>a){s=(a+b+c)/2;area=(float)sqrt(s*(s-a)*(s-b)*(s-c));printf("area=%f\n",area);}else{printf("不是三角形");}}5.4#include<stdio.h>#include<math.h>main(){float a,b,c,x,y;printf("Inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);if(a==0){printf("该方程不是一元二次方程\n");}if(b*b-4*a*c>0){x=(-b+sqrt(b*b-4*a*c))/(2*a);y=(-b-sqrt(b*b-4*a*c))/(2*a);printf("x=%f,y=%f\n",x,y);}else if(b*b-4*a*c==0)x=-b/(2*a);y=-b/(2*a);printf("x=%f,y=%f\n",x,y);}else{printf("该方程无实根\n");}}5.5#include<stdio.h>main(){int year,flag;printf("Input a year:");scanf("%d",&year);if(year%4==0&&year%400!=0||year%400==0){flag=1;}else{flag=0;}if(flag==1){printf("%d is a leap year!\n",year);}else{printf("%d is not a leap year!\n",year);}}5.6#include<stdio.h>main(){int year,flag;printf("Input a year:");scanf("%d",&year);flag=year%400==0||year%4==0&&year%100!=0?1:0;if(flag==1&&flag!=0){printf("%d is a leap year!\n",year);}else{printf("%d is not a leap year!\n",year);}}5.7#include<stdio.h>main(){char ch;printf("Inputch:");scanf("%c",&ch);if(ch>='a'&&ch<='z'){ch=getchar();ch=ch-32;printf("%c,%d\n",ch,ch);}else if(ch>='A'&&ch<='Z'){ch=getchar();ch=ch+32;printf("%c,%d\n",ch,ch);}else{printf("%c",ch);}}5.8#include<stdio.h>main(){char ch;printf("Inputch:");scanf("%c",&ch);if(ch>=48&&ch<=57){printf("ch是数字字符\n");}else if(ch>=65&&ch<=90){printf("ch是大写字母\n");}else if(ch>=97&&ch<=122){printf("ch是小写字母\n");}else if(ch==32){printf("ch是空格\n");}else{printf("ch是其他字符\n");}}5.9#include<stdio.h>main(){int score,grade;printf("Input score:");scanf("%d",&score);grade=score/10;if(score<0||score>100){printf("Input error\n");}if(score>=90&&score<=100){printf("%d--A\n",score);}else if(score>=80&&score<90){printf("%d--B\n",score);}else if(score>=70&&score<80){printf("%d--C\n",score);}else if(score>=60&&score<70){printf("%d--D\n",score);}else if(score>=0&&score<60){printf("%d--E\n",score);}}5.10#include<stdio.h>main(){int year,month;printf("Input year,month:");scanf("%d,%d",&year,&month);if(month>12||month<=0){printf("error month\n");}else{switch(year,month){case12:case10:case8:case7:case5:case3:case1:printf("31天\n");break;case11:case9:case6:case4:printf("30天\n");break;case2:if(year%4==0&&year!=0||year%400==0){printf("29天\n");}else{printf("28天\n");}break;default:printf("Input error\n");}}}6.1(1)#include<stdio.h>main(){int i,j,k;char space='';for(i=1;i<=4;i++){for(j=1;j<=i;j++){printf("%c",space);}for(k=1;k<=6;k++){printf("*");}printf("\n");}}6.1(2)#include<stdio.h>main(){int k=4,n;for(n=0;n<k;n++){if(n%2==0)continue;k--;}printf("k=%d\n,n=%d\n",k,n);}6.1(3)#include<stdio.h>main(){int k=4,n;for(n=0;n<k;n++){if(n%2==0)break;k--;}printf("k=%d,n=%d\n",k,n);}6.2(1)#include<stdio.h>main(){int i,sum=0;for(i=1;i<=101;i++){sum=sum+i;}printf("sum=%d\n",sum);}6.2(2)#include<stdio.h>main(){long i;long term,sum=0;for(i=1;i<=101;i=i+2){term=i*(i+1)*(i+2);sum=sum+term;}printf("sum=%ld\n",sum);}6.2(4)#include<stdio.h>#include<math.h>main(){int n=1;float term=1.0,sign=1,sum=0;while(term<=-1e-4||term>=1e-4){term=1.0/sign;sum=sum+term;sign=sign+n;n++;}printf("sum=%f\n",sum);}6.2(5)#include<stdio.h>#include<math.h>main(){int n=1,count=1;float x;double sum,term;printf("Input x:");scanf("%f",&x);sum=x;term=x;do{term=-term*x*x/((n+1)*(n+2));sum=sum+term;n=n+2;count++;}while(fabs(term)>=1e-5);printf("sin(x)=%f,count=%d\n",sum,count);}6.3#include<stdio.h>main(){int x=1,find=0;while(!find){if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0){printf("x=%d\n",x);find=1;x++;}}}/*int x,find=0;for(x=1;!find;x++){if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0){printf("x=%d\n",x);find=1;}}}*/6.4#include<stdio.h>main(){int i,n;long p=1,m=1;printf("Input n:");scanf("%d",&n);for(i=1;i<=n;i++){p=i*i;m=i*i*i;printf("p=%d,m=%d\n",i,p,i,m);}}6.5#include<stdio.h>main(){float c,f;for(c=-40;c<=110;c=c+10){f=9/5*c+32;printf("f=%f\n",f);}}6.6#include<stdio.h>#include<math.h>main(){int n;double c=0.01875,x;do{x=x*pow(1+c,12)-1000;n++;}while(x>0);printf("x=%d\n",x);}6.7#include<stdio.h>main(){int n=0;float a=100.0,c;printf("Inputc:");scanf("%f",&c);do{a=a*(1+c);n++;}while(a<=200);printf("n=%d\n",n);}6.8#include<stdio.h>#include<math.h>main(){int n=1,count=1;double sum=1,term=1;while(fabs(term)>=1e-5){term=pow(-1,count)*(1.0/(n+2));sum=sum+term;n=n+2;count++;}sum=4*sum;printf("sum=%f,count=%d\n",sum,count); }6.9#include<stdio.h>#include<math.h>main(){int n=1,count=1;double sum=1,term=1;while(fabs(term)>=1e-5){term=term*(1.0/n);sum=sum+term;n++;count++;}printf("sum=%f,count=%d\n",sum,count);}6.10#include<stdio.h>#include<math.h>main(){int x;for(x=100;x<=999;x++){if(x==pow(x/100,3)+pow(x/10%10,3)+pow(x%10,3))printf("x=%d\n",x);}}6.11#include<stdio.h>main(){int i=0,n;long sum=0,term=1;printf("Inputn:");scanf("%d",&n);do{i++;term=term*i;sum=sum+term;}while(sum<n);printf("%d\n",i-1);}6.12#include<stdio.h>main(){int i,n,m,count=0,sum=0;printf("Input n:");scanf("%d",&n);for(i=1;i<=n;i++){printf("Inputm:");scanf("%d",&m);if(m>0){sum=sum+m;count++;}else{break;}printf("sum=%d,count=%d\n",sum,count);}}6.13#include<stdio.h>main(){int i,n,m,count=0,sum=0;printf("Inputn:");scanf("%d",&n);for(i=1;i<=n;i++){printf("Inputm:");scanf("%d",&m);if(m>0||m<0){sum=sum+m;count++;}else{break;}printf("sum=%d,count=%d\n",sum,count);}}6.14#include<stdio.h>main(){int x,y,z;for(x=0;x<=17;x++){for(y=0;y<=25;y++){3*x+2*y+z==50;z=30-x-y;if(3*x+2*y+z==50&&x+y+z==30)printf("x=%d,y=%d,z=%d\n",x,y,z);}}}6.15#include<stdio.h>main(){int x,y;for(x=0;x<=98;x++){y=98-x;2*x+4*y==386;if(x+y==98&&2*x+4*y==386){printf("x=%d,y=%d\n",x,y);}}}6.16#include<stdio.h>main(){int x,y,z;for(x=0;x<=20;x++){for(y=0;y<=33;y++){3*y+5*x+z/3.0==100;z=100-x-y;if(5*x+3*y+z/3.0==100&&z+x+y==100){printf("x=%d,y=%d,z=%d\n",x,y,z);}}}}6.17#include<stdio.h>main(){int x,y,z;for(x=1;x<=9;x++){for(y=1;y<=17;y++){10*x+5*y+z==100;z=50-x-y;if(10*x+5*y+z==100&&x+y+z==50&&z>0){printf("x=%d,y=%d,z=%d\n",x,y,z);}}}}7.1#include<stdio.h>int Square(int i){return i*i;}int main(){int i=0;i=Square(i);for(;i<3;i++){static int i=1;i+=Square(i);printf("%d,",i);}printf("%d\n",i);return0;}7.2#include<stdio.h>int hour,minute,second;void update(){second++;if(second==60){second=0;minute++;}if(minute==60){minute=0;hour++;}if(hour==24)hour=0;}void display(){printf("%d,%d,%d\n",hour,minute,second); }void delay(){int t;for(t=0;t<100000000;t++);}int main(){int i;void updaye(),display(),delay();for(i=0;i<1000000;i++){update();display();delay();}return0;}7.3#include<stdio.h>int GetMax(int a,int b);int main(){int x,y,max;printf("Inputx,y:");scanf("%d,%d",&x,&y);max=GetMax(x,y);printf("max=%d\n",max);return0;}int GetMax(int m,int n){if(m>=n)return m;elsereturn n;}7.4#include<stdio.h>int LCM(int n,int m);int main(){int a,b;printf("Inputa,b:");scanf("%d,%d",&a,&b);printf("%d\n",LCM(a,b));return0;}int LCM(int n,int m){int x;int find=0;for(x=1;!find;x++){if(x%n==0&&x%m==0){find=1;}}return x-1;}7.5#include<stdio.h>long Fact(int n);int main(){int m,a;printf("Inputm:");scanf("%d",&m);for(a=1;a<=m;a++){printf("%d!=%ld\n",a,Fact(a));}return0;}long Fact(int n){int i;long result=1;for(i=2;i<=n;i++)result*=i;return result;}7.6#include<stdio.h>long Fact(int n);int main(){int m;long ret;printf("Inputm:");scanf("%d",&m);ret=Fact(m);printf("ret=%d\n",ret);return0;}long Fact(int n){int i;long result=1,sum=0;for(i=2;i<=n;i++){result*=i;sum=sum+result;}return sum;}7.7(1)#include<stdio.h>int Gcd(int a,int b);int main(){int m,n;printf("Inputm,n:");scanf("%d,%d",&m,&n);printf("%d\n",Gcd(m,n));return0;}int Gcd(int a,int b){int t,min,find=0;min=a<b?a:b;t=min;for(t=min;!find;t--){a%t==0;b%t==0;if(a%t==0&&b%t==0)return t;}find=1;}7.7(2)#include<stdio.h> int Gcd(int a,int b);int main(){int m,n;printf("Inputm,n:");scanf("%d,%d",&m,&n);printf("%d\n",Gcd(m,n));return0;}int Gcd(int a,int b){int r,temp;r=a%b;if(r==0)return b;elsedo{temp=b;b=r;a=temp;r=a%b;}while(r!=0);return b;}8.1(1)#include<stdio.h> void Func(int x){x=2;}int main(){int x=10;Func(x);printf("%d",x);return0;}8.1(2)#include<stdio.h> void Func(int b[]){int j;for(j=0;j<4;j++){b[j]=j;}}int main(){static int a[]={5,6,7,8},i;Func(a);for(i=0;i<4;i++){printf("%d",a[i]);}return0;}8.2(1)int PositiveNum(int a[],int n) {int i,count=0;for(i=0;i<n;i++){if(a[i]>0)count++;}return0;}8.2(2)void Fib(long f[],long n){int i;f[0]=0;f[1]=1;for(i=2;i<n;i++){f[i]=f[i-1]+f[i-2];}}8.2(3)#include<stdio.h>int main(){int a[10],n,max,min,maxPos,minPos;for(n=0;n<10;n++){scanf("%d",&a[n]);}max=min=a[0];maxPos=minPos=0;for(n=0;n<10;n++){if(a[n]>max){max=a[n];maxPos=n;}else if(a[n]<min){min=a[n];minPos=n;}}printf("max=%d,pos=%d\n",max,maxPos);printf("min=%d,pos=%d\n",min,minPos);return0;}8.3void DivArray(int*pArray,int n){int i;for(i=0;i<n;i++){pArray[i]/=pAttay[0];}}8.4#include<stdio.h>#define N40int FailNum(int score[],int n);void ReadScore(int score[],int n);int main(){int score[N],n;printf("Input n:");scanf("%d",&n);ReadScore(score,n);FailNum(score,n);printf("FailNum students are%d\n",FailNum(score,n));return0;}int FailNum(int score[],int n){int i,count=0;for(i=0;i<n;i++){if(score[i]<60)count++;}return count;}void ReadScore(int score[],int n){int i;printf("Input score:");for(i=0;i<n;i++){scanf("%d",&score[i]);}}8.5#include<stdio.h>#define N40int HighAver(int score[],int n);int ReadScore(int score[]);int main(){int score[N],n;n=ReadScore(score);printf("HighAver students are%d\n",HighAver(score,n));return0;}int HighAver(int score[],int n){int i,count=0,sum=0,aver;for(i=0;i<n;i++){sum=sum+score[i];aver=sum/n;}for(i=0;i<n;i++){if(score[i]>aver)count++;}return count;}int ReadScore(int score[]){int i=-1;do{i++;printf("Input score:");scanf("%d",&score[i]);}while(score[i]>=0);return i;}8.6#include<stdio.h>#define N40int ReadScore(int score[],long num[]);int FindMax(int score[],long num[],int n);int main(){int score[N],n,max,num,t;long num[N];t=FindMax(score,n);max=score[t];num=num[t];printf("max=%d,num=%d\n",max,num);return0;}int ReadScore(int score[],long num[]){int i=-1;do{i++;printf("Input student's ID and score:");scanf("%ld%d",&num[i],&score[i]);}while(num[i]>0&&score[i]>=0);return i;}int FindMax(int score[],long num[],int n){int max,i;max=score[0];for(i=1;i<n;i++){if(score[i]>max)max=score[i];}return i;}8.7#include<stdio.h>#define N40int Read(int a[]);int ChangeArry(int a[],int n);int main(){int a[N],n;printf("%d\n",ChangeArry(a,n));return0;}int Read(int a[]){int i;for(i=0;i<9;i++){printf("Input a:");scanf("%d",&a[i]);return i;}int ChangeArry(int a[],int n){int max,min,i,maxpos,minpos,term;max=min=score[0];for(i=1;i<n;i++){if(a[i]>max)max=score[i];maxpos=n;else(a[i]<min)min=a[i];minpos=n;temp=maxpos;maxpos=minpos;minpos=temp;}return a[i];}8.10#include<stdio.h>#define N5void main(){int a[N][N];int sum=0;int i,j;printf("请输入一个%d*%d的矩阵\n",N,N);for(i=0;i<N;i++){for(j=0;j<N;j++){scanf("%d",&a[i][j]);}}for(i=0;i<N;i++){for(j=0;j<N;j++){if(i==j||i+j==N-1)sum=sum+a[i][j];}}printf("对角线元素之和为：%d\n",sum);}8.11#include<stdio.h>#define N2#define M3void main(){int a[N][M],b[N][M];int i,j,sum1=0,sum2=0,sum=0;printf("请输入一个%d*%d的矩阵\n",N,M);for(i=0;i<N;i++){for(j=0;j<M;j++){scanf("%d",&a[i][j]);sum1=sum1+a[i][j];}}printf("请输入一个%d*%d的矩阵\n",N,M);for(i=0;i<N;i++){for(j=0;j<M;j++){scanf("%d",&b[i][j]);sum2=sum2+a[i][j];}}sum=sum1+sum2;printf("sum=%d\n",sum);}8.12#include<stdio.h>#define N7void YangHui(int a[N][N],int n);void main(){int i,j,n,b[N][N];printf("Input n:");scanf("%d",&n);YangHui(b,n);for(i=0;i<n;i++){for(j=0;j<=i;j++){printf("%4d",b[i][j]);}printf("\n");}}void YangHui(int a[N][N],int n){int i,j;for(i=0;i<n;i++){a[i][0]=1;a[i][i]=1;}for(i=2;i<n;i++){for(j=1;j<i;j++)a[i][j]=a[i-1][j-1]+a[i-1][j];}}8.13#include<stdio.h>#define N12void main(){int i;int f[N]={1,1};printf("%d:%d\n",0,f[0]);printf("%d:%d\n",1,f[1]);for(i=2;i<N;i++){f[i]=f[i-1]+f[i-2];printf("%d:%d\n",i+1,f[i]);}}8.14#include<stdio.h>#include<stdlib.h>#include<time.h>#define N6000void main(){int a[N],i;int b1=0,b2=0,b3=0,b4=0,b5=0,b6=0;float p1,p2,p3,p4,p5,p6;srand(time(NULL));for(i=0;i<N;i++){a[i]=rand()%6+1;printf("%3d",a[i]);if(a[i]==1)b1++;if(a[i]==2)b2++;if(a[i]==3)b3++;if(a[i]==4)b4++;if(a[i]==5)b5++;if(a[i]==6)b6++;p1=(float)(b1/6000.0);p2=(float)(b2/6000.0);p3=(float)(b3/6000.0);p4=(float)(b4/6000.0);p5=(float)(b5/6000.0);p6=(float)(b6/6000.0);}printf("骰子出现1的概率：%.2f\n",p1);printf("骰子出现2的概率：%.2f\n",p2);printf("骰子出现3的概率：%.2f\n",p3);printf("骰子出现4的概率：%.2f\n",p4);printf("骰子出现5的概率：%.2f\n",p5);printf("骰子出现6的概率：%.2f\n",p6);}9.1(1)void Swap(int*x,int*y){int*pTemp;//*pTemp未进行初始化，*pTemp指向哪里位置*pTemp=*x;*x=*y;*y=*pTemp;}9.1(2)void Swap(int*x,int*y){int*pTemp;pTemp=x;x=y;y=pTemp;}//错误，x,y没有指向类型9.2#include<stdio.h>int main(){int a[]={1,2,3,4,5};int*p=a;printf("%d,%d,%d,%d,%d,%d,%d\n",*p,*(++p),(*p)++,*p,*p--,--(*p),*p);return0;}9.3#include<stdio.h>void Swap(int*x,int*y);int main(){int a[6]={1,2,3,4,5,6},b[6]={11,22,33,44,55,66};int i;printf("Before Array\n");for(i=0;i<6;i++){printf("%d\n",a[i]);}for(i=0;i<6;i++){printf("%d\n",b[i]);}for(i=0;i<6;i++){Swap(&a[i],&b[i]);}printf("After Array\n");for(i=0;i<6;i++){printf("%d\n",a[i]);}for(i=0;i<6;i++){printf("%d\n",b[i]);}return0;}void Swap(int*x,int*y){int temp;temp=*x;*x=*y;*y=temp;}9.4#include<stdio.h>#define N10void FindMaxMin(int a[],int*pMaxa,int*pMaxnum,int*pMina,int*pMinnum);int main(){int a[N];int i,maxa,mina,maxnum,minnum;printf("Input a:");for(i=0;i<10;i++){scanf("%d",&a[i]);}FindMaxMin(a,&maxa,&maxnum,&mina,&minnum);printf("maxa=%d,maxnum=%d,mina=%d,minnum=%d\n",maxa,maxnum,mina,minnum);return0;}void FindMaxMin(int a[],int*pMaxa,int*pMaxnum,int*pMina,int*pMinnum){int i;*pMaxa=a[0];*pMina=a[0];*pMaxnum=0;*pMinnum=0;for(i=0;i<10;i++){if(a[i]>*pMaxa){*pMaxa=a[i];*pMaxnum=i;}else if(a[i]<*pMina){*pMina=a[i];*pMinnum=i;}}}10.1void MYStrcpy(char*dstStr,const char*srcStr){while((*dstStr++=*srcStr++)!='\0'){}}10.2#include<stdio.h>main(){char*a="main(){char*a=%c%s%c;printf(a,34,a,34);}";printf(a,34,a,34);} 10.3(1)unsigned int MyStrlen(char*p)main(){unsigned int len;len=0;for(;*pa!='\0';pa++){len++;}return len;}10.3(2)unsigned int MyStrlen(char s[]){char*p=s;while(*p!='\0'){p++;}return(p-*p);}10.3(3)int MyStrcmp(char*p1,char*p2){for(;*p1==*p2;p1++,p2++){if(*p1=='\0')return-1;}return1;}10.3(4)int MyStrcmp(char s[],char t[]){int i;for(i=0;s[i]==t[i];i++){if(s[i]=='\0')return0;}return i;}10.3(5)#include<stdio.h>#include<string.h>int main(){char password[7]="secret";char userInput[81];printf("Input Password:");scanf("%s",userInput);if(strcmp(userInput,password)==0)printf("Coorrect password!Welcome to the system...\n");else if(strcmp(userInput,password)<0)printf("Invalid password!user input<password...\n");elseprintf("Invalid password!user input>password...\n");return0;}10.4#include<stdio.h>#define N24unsigned int CountLetter(char str[]);int main(){char a[N];printf("Input a letter:\n");gets(a);printf("The length of the letter is:%d\n",CountLetter(a));return0;}unsigned int CountLetter(char str[]){char*p=str;int c=0,flag=0;while(*p!='\0'){if(*p!='')flag=1;else if(flag==1){c++;flag=0;}p++;}return c+1;}12.1#include<stdio.h>typedef struct data{int year;int month;int day;}DATA;typedef struct work{char a[14];char b[10];char c[6];}WORK;typedef struct student{char studentName[10];char studentSex;DATA birthday;WORK profession;}STUDENT;int main(){STUDENT stu={"王刚",'M',{1991,5,19},{"信息工程系","学习人员","学生"}};printf("stu:%2s%3c%6d/%02d/%02d%4s,%4s,%4s\n",stu.studentName,stu.studentSex,st u.birthday.year,stu.birthday.month,stu.birthday.day,stu.profession.a,stu.profession.b,stu.profession.c);return0;}12.4#include<stdio.h>#include<string.h>#define N10typedef struct people{char peopleName[10];}PEOPLE;int main(){int sum1=0,sum2=0,sum3=0,sum4=0;int i;char name[N][N];PEOPLE stu[5]={"zhang","li","wang"};printf("Enter their name:\n");for(i=0;i<10;i++){gets(name[i]);if(strcmp(name[i],stu[0].peopleName)==0)sum1++;else if(strcmp(name[i],stu[1].peopleName)==0) sum2++;else if(strcmp(name[i],stu[2].peopleName)==0) sum3++;elsesum4++;}printf("stu:%4s%2d\n",stu[i].peopleName,sum[j]);printf("stu:%4s%2d\n",stu[1].peopleName,sum2);printf("stu:%4s%2d\n",stu[2].peopleName,sum3);printf("%2d\n",sum4);return0;}精品文档。
C语言课堂笔记信息工程学院软件技术1班张龙彪1.一个标准C程序必须有且仅有一个main函数（主函数），标准C程序总是从main开始执行，与main所在位置无关。
2.除复合语句外，C语句都是以分号作为结束标志。
（建议一行只写一条语句）。
3.关键字（保留字）：C语言中预先规定的具有固定含义的一些单词。
用户只能按照其预定含义使用，不得擅自改变意思。
此类关键字有：auto break case char const continue default do double else enum extern float for goto if int long register return short signed sizeof static struct switch typedef union unsigned void volatile while。
4.标识符：分为系统定义标识符和用户自定义标识符两类。
系统定义标识符（允许用户赋予其新含义）如main、库函数名printf、scanf等。
用户自定义标识符如add 变量x、y、sum等。
5.分隔符：空格回车或换行（程序中相邻的关键字、标识符之间等形式）逗号(相邻同类项之间的分隔)。
6.其他符号：花括号：{} /* */ 。
8.常用运算符的优先级与结合性【习题2】习题所涉知识点：①变量命名：由字母、数字和下划线组成，第一位只能为字母或下划线，不饿能和C中保留字完全相同。
②逻辑值“真”“假”判断：整数值0表示假，其他true，和任何非0数值均表示真。
③字符常量：’’（单引号）括起来的单个普通字符或转义字符。
常用转义序列：编程提示：每次按下Tab键，并不是从当前的光标位置向后移动一个Tab的宽度，而是移动到下一个制表位，实际移动的宽度视当前光标的位置距相邻的下一个制表位的距离而定。
④字符串常量：有一对双引号括起来的一个字符序列，Eg. “qwer”“123”“w”等等。
c语言程序设计苏小红第二版课后答案C语言作为一门古老而强大的编程语言，至今仍然在各个领域中发挥着重要作用。
苏小红教授的《C语言程序设计》第二版是一本广受好评的教材，它不仅系统地介绍了C语言的基础知识，还通过丰富的实例和练习题帮助读者加深理解。
以下是该书部分课后习题的答案解析，以供参考。
第一章：C语言概述1. 问题：C语言的特点是什么？答案：C语言的特点包括简洁高效、结构化、可移植性高、丰富的运算符、数据类型丰富等。
2. 问题：C语言的发展历程是怎样的？答案：C语言起源于20世纪70年代，由丹尼斯·里奇（Dennis Ritchie）在贝尔实验室开发，最初用于UNIX操作系统的编写。
随着UNIX的流行，C语言也逐渐被广泛使用。
第二章：数据类型、运算符和表达式1. 问题：C语言中的基本数据类型有哪些？答案：C语言中的基本数据类型包括整型（int）、字符型（char）、浮点型（float和double）等。
2. 问题：算术运算符有哪些？答案：算术运算符包括加（+）、减（-）、乘（*）、除（/）和模运算（%）。
第三章：控制语句1. 问题：if语句的基本形式是什么？答案：if语句的基本形式是：```cif (条件) {// 条件为真时执行的代码} else {// 条件为假时执行的代码}```2. 问题：for循环的一般形式是什么？答案：for循环的一般形式是：```cfor (初始化表达式; 条件表达式; 迭代表达式) {// 循环体}```第四章：数组1. 问题：一维数组的声明方式是什么？答案：一维数组的声明方式是：```c类型数组名[数组大小];```2. 问题：如何使用数组？答案：使用数组时，可以通过数组名和索引来访问数组元素，例如： ```cint arr[10];arr[0] = 1; // 给数组的第一个元素赋值```第五章：函数1. 问题：函数的定义包括哪些部分？答案：函数的定义包括返回类型、函数名、参数列表和函数体。
一、选择题1. 对一维数组a的正确说明是 D 。
A) int a(10); B) int n=10,a[n]; C) int n;D) #define SIZE 10scanf("%d",&n); inta[SIZE];int a[n];2. 能对二维数组a进行正确初始化的语句是 B 。
A) int a[2][]={{1,0,1},{5,3,2}}; B) int a[][3]={{1,2,3},{4,5,6}};C) int a[2][4]={{1,2,3},{4,5},{6}}; D）inta[][3]={{1,0,1},{1,2,3,4},{1,1}};3. 对两个数组 a和 b进行如下初始化char a[]="ABCDEF";char b[]={'A','B','C','D','E','F'};则以下叙述正确的是 D 。
A) a与b数组完全相同B) a与b长度相同C) a和b中都存放字符串D) a数组比b数组长度长4. 以下数组定义中不正确的是 D 。
A) int a[2][3]; B) int b[][3]={0,1,2,3,4,5};C) int c[100][100]={0}; D) intd[3][]={{1,2},{1,2,3},{1,2,3,4}};5. 以下选项中，不能正确赋值的是 A 。
A) char s1[10];s1="Ctest"; B) char s2[]={'C', 't', 'e', 's','t'};C) char s3[20]="Ctest"; D) chars4[]="Ctest\n"二、阅读程序写出结果1.#include<stdio.h>void main(){ char ch[7]={"12ab56"};int i,s=0;for(i=0;ch[i]>='0'&&ch[i]<='9';i+=2)s=10*s+ch[i]-'0';printf("%d\n",s);}答案：12.#include<stdio.h>void main(){ int a[10]={1,2,2,3,4,3,4,5,1,5};int n=0,i,j,c,k;for(i=0;i<10-n;i++){ c=a[i];for(j=i+1;j<10-n;j++)if(a[j]==c){ n++;for(k=j;k<10-n;k++)a[k]=a[k+1];}}for(i=0;i<(10-n);i++)printf("%d",a[i]);}答案：123453.#include <stdio.h>void main(){ int i;char a[]="Time",b[]="Tom";for(i=0;a[i]!='\0'&&b[i]!='\0';i++)if(a[i]==b[i])if(a[i]>='a'&&a[i]<='z')printf("%c",a[i]-32);elseprintf("%c",a[i]+32);else printf("*");}答案： t*M4.#include<stdio.h>#define LEN 4void main(){ int j,c;static char n[2][LEN+1]={"8980","9198"}; for(j=LEN-1;j>=0;j--){c=n[0][j]+n[1][j]-2*'0';n[0][j]=c%10+'0';}for(j=0;j<=1;j++) puts(n[j]);}答案：7078 9198三、程序填空1.程序的功能是在a数组中查找与x值相同的元素的所在位置。
