1.猜数字游戏
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main()
{
int ret;
int num=0;
srand((unsigned int)time(NULL));
ret=rand()%100;
scanf("%d",&num);
while(num!=ret)
{
if(num>ret)
{
printf("too big!\n");
}
if(num<ret)
{
printf("too small!\n");
}
scanf("%d",&num);
}
printf("right!");
return 0;
}
2.binsearch
#include<stdio.h>

int binsearch(int a,int arr[],int left,int right)
{
int mid;
mid=left-(left-right)/2;
while(left!=right)
{
if(a<=arr[mid])
{

if(a==arr[mid])
{
return mid;
}
else
right=mid-1;
}
else if(a>arr[mid])
{
left=mid+1;
}
mid=left-(left-right)/2;
}
if(a==arr[mid])
return mid;
else
return -1;
}
int main()
{
int arr[]={1,3,5,7,8,10};
int left=0;
int right=sizeof(arr)/sizeof(arr[0])-1;
int temp=binsearch(3,arr,left,right);
printf("%d ",temp);
return 0;
}
3.输出行号
#include<stdio.h>

int main()
{
char ch;
int i=1;
while((ch=getchar())!=EOF)
{
printf("%d ",i++);
while((ch=getchar())!='\n')
{
putchar(ch);
}
printf("\n");
}
return 0;
}
4.找出最大和最小值
#include<stdio.h>

int main()
{
int arr[]={1,2,3,4,5,6,7,8,9,10};
int max;
int min;
int i;
max=arr[0];
min=arr[0];
for(i=1;i<10;i++)
{
if(max<=arr[i])
max=arr[i];
}
for(i=1;i<10;i++)
{
if(min>=arr[i])
min=arr[i];
}
printf("max=%d  min=%d",max,min);
return 0;
}
5.组合无重复数
#include<stdio.h>

int main()
{
int i,j,m;
for(i=1;i<5;i++)
{
for(j=1;j<5;j++)
{
if(j==i)
continue;
for(m=1;m<5;m++)
{if(m==i||m==j)
continue;
printf("%d ",i*100+j*10+m);
}
}
}
return 0;
}