C语言复习考点

三角形面积#include<stdio.h>#include<math.h>void main(){double a,b,c,s,area;scanf("%1f,%1f,%1f",&a,&b,&c);s=(a+b+c)/2;area=sqrt(s*(s-a)*(s-b)*(s-c));printf("area=%1f\n",area);}三位数反序输出#include"stdio.h"void main(){int a,b,c,x,y;printf("输入一个3位数：\n");scanf("%d",&x);a=x%10;b=x/100;c=x%100/10;y=a*100+c*10+b;printf("%d\n",y);}判断该天是这一年的第几天#include "stdio.h"void main(){int year,month,day,days,i,d;printf("请输入年，月，日:");scanf("%d,%d,%d",&year,&month,&day);days=0;for(i=1;i<month;i++){switch(i)case1:case3:case5:case8:case10:case12 :d=31;break;case4:case6:case9:case11:d=30;break;case2:if(year%400==0)d=29;elsed=28;}days+=d;}从键盘输入一个数，将其插入到一个降序数组中，保持数组仍然降序排列#include"stdio.h"void main(){int data,temp,k;int a[9]={50,25,15,10,8,4,2,-10};printf("Enter a data:");scanf("%d",&data);int a[k],a[k-1];for(k=8;k>0;k--)if(a[k]>a[k-1]){temp=a[k];a[k]=a[k-1];a[k-1]=temp;}else a[k]=a[k-1];for(k=0;k<=8;k++)printf("%5d",a[k]);用fun求平均值#include"stdio.h"void fun(int i,int j,int k);void main(){int x,y,z;x=4,y=12,z=6;fun(x,y,z);printf("x=%d,y=%d,z=%d",x,y,z);}void fun(int i,int j,int k){int t;t=(i+j+k)/3;printf("t=%d\n",t);}用power求x的n次方#include"stdio.h" float power(float x,int n);void main(){int x,y;int n;scanf("%d",&n,&x);y=power(x,n);printf("%8.2f\n",y);}float power(float x,int n){int i;float t;t=1;for(i=1;i<=n;i++)t=t*x;return t;}判断是否为素数int prime(int x){int i,flag=1;for(i=2;i<x;i++)if(x%i==0){flag=0;break;}return flag;}void main(){int m;scanf("%d",&m);if(prime(m))printf("%d是素数!\n",m);elseprintf("%d不是素数!\n",m);}统计数组中数字，字母以及其他字符的个数并输出#include"stdio.h"#include"string.h"Void count(char a[]){Int sum1=0,sum2=0,sum3=0;For(i=0;a[i]!=’\0’;i++)If(a[i]>=’a’&&a[i]<=’z’||a[i]>=’A’&&a[i]<=’Z’) sum1++Else if (a[i]>=‘0’&&a[i]<=‘9’) sum2++ ；else sum3++;printf (“sum1=%d,sum1=%d,sum1=%d\n”,sum1,sum2,sum3);}Void main(){Char string[81];Printf(“input string:\n”);scanf("%s",string);count(string);}冒泡法#include<stdio.h>void main(){int i,j,a[5],temp;for(i=0;i<5;i++){printf("please input a number a[%d]=",i);scanf("%d",&a);}for(i=4;i>0;i--){for(j=4;j>4-i;j--){if(a[j-1]>a[j]){temp=a[j-1];a[j-1]=a[j];a[j]=temp;}}}for(i=0;i<5;i++)printf("%d\t",a);}将a和b的对应位置字符较大者存放到数组c中#include "stdio.h"#include "string.h"void main(){*p!='\0'//*q!='\0'*p>*qq++定义函数int f（char*），统计所指字符串中字母数字和其他字符的个数#include "stdio.h"#include "string.h"void main(){int f(char*x);char arra[100];int len ;gets(arra);len=f(arra);printf("%d",len);{int f(char*x);}int len=strlen(x);return len;}定义函数int f（char*）判断x所指的是否是回文是则返回1#include "stdio.h"#include "string.h"void main(){int f(char *x);char a[100];int flag;gets(a);flag=f(a);printf("%d\n",flag);}int f(char *x){int flag=1;int len=strlen(x);char *t1,*t2;t1=x;t2=x+len-1;while (*t1!=*t2){if(*t1!=*t2){flag=0;break;}*t1++;*t2++;}return flag;}1、编程实现：从键盘输入3个变量的值，其中中a=5，b=6,c=7，然后将3个变量的值进行交换，使得a=6,b=7,c=5.#include"stdio.h"void main(){int a,b,c,m;printf("Enter a,b,c:");scanf("%d,%d,%d",&a,&b&c);m=a;a=b;b=c;c=m;printf("a=%d,b=%d,c=%d\n",a,b,c);}2、求∑n!(1!+2!+3!+...+25!)。

（n从1到25）#include<stdio.h>void main(){float sum=1,term=0;for(i=1;i<=25;i++){sum=sum*i;term=term+sum;}printf("%d,%f\n",i,term);}。