1.函数

#include<stdio.h>void Add(int *p)
{(*p)++;
}int main()
{int time=0;Add(&time);printf("%d\n",time);return 0;
}

2.二分查找

#include<stdio.h>void Add(int *p)
{(*p)++;
}int main()
{int time=0;Add(&time);printf("%d\n",time);return 0;
}
[hym@VM-4-7-centos C_0610]$ cat binary_search.c
#include<stdio.h>int binary_search(int arr[],int k,int sz)
{int left = 0;int right = sz-1;while(left<=right){int mid = (left+right)/2;if(arr[mid]==k)return mid;else if(arr[mid]>k)right = mid-1;elseleft = mid+1;}  return -1;
}int main()
{int arr [] = {1,2,3,4,5,6,7,8,9,10};int k = 7;int length = sizeof(arr)/sizeof(arr[0]);int ret = binary_search(arr,k,length);if(ret == -1){printf("找不到\n");}else{printf("序号为%d\n",ret);}return 0;
}

3.函数调用

#include<stdio.h>void fun(void)
{printf("hehe\n");
}int main()
{fun();return 0;
}

4.  分文件编写

#include<stdio.h>
#include"test2.h"int main()
{int ret = add(30,20);printf("%d\n",ret);return 0;
}
[hym@VM-4-7-centos C_0610]$ cat add.c
#include<stdio.h>void Add(int *p)
{(*p)++;
}

#include"test2.h"
int add(int x,int y)
{return x+y;
}

5.函数

#include<stdio.h>int get_max(int num1,int num2)
{return num1>num2?num1:num2;
}int main()
{int a = 10;int b = 20;int max = get_max(a,b);printf("%d\n",max);return 0;
}

 

6.memset用法

#include<stdio.h>
#include<memory.h>int main()
{char arr[] = "hello world"; memset(arr,'x',5);printf("%s\n",arr);return 0;
}

 

 7.0到200的素数个数

#include<stdio.h>int is_prime(int n)
{int i = 0;for(i=2;i<n;i++){if(n%i==0)return 0;}return 1;
}int main()
{int count=0;int i = 0;for(i = 100;i <= 200;i++){if(is_prime(i)==1){count++;printf("%d\n",i);}}printf("count = %d\n",count);return 0;
}

 8.strcpy用法

#include<stdio.h>
#include<string.h>int main()
{char arr1[] = "abcdef";char arr2[] = {};strcpy(arr2,arr1);printf("%s\n",arr2);return 0;
}

9. 函数调用

#include<stdio.h>void swap(int* x,int* y)
{int tmp = *x;*x = *y;*y = tmp;
}int main()
{int a =10; int  b = 20;printf("a=%d,b=%d",a,b);swap(&a,&b);printf("a=%d,b=%d",a,b);return 0;
}

 10.计算闰年

#include<stdio.h>int is_leap_year(int y)
{if(y%4==0 && y%100!=0)return 1;else if(y%400 ==0)return 1;elsereturn 0;
}int main()
{int year = 0;for(year = 1000;year<=2000;year++){if(is_leap_year(year)==1){printf("%d ",year);}}
}