c语言的二分查找简单实例

/*********************************** *二分查找：使用于有序排列的集合体 *data:2017.8.17 *Author:shi **********************************/#include int data_serch(int arry[],int left,int right,int data){int mid;mid = (right/2) - 1;//中间元素的下标while(left <= right){//当左界限大于右界限时，表明已查找完毕if(data > arry[mid]){left = mid+1;//左界限移动到上次中间的地方，即中间值下标值+1mid = (left + right)/2;//中间值下标也要变化}else if(data < arry[mid]){right = mid-1;mid = (left + right)/2;}elsereturn mid;//返回中间值的下标}return -1;//当没有这个数字的时候返回}int main(void){int arry[11] = {1,2,3,4,5,6,7,8,9,10,11};int right = 0;int left = 0;int data,ret;printf("输入要查找的数:  ");scanf("%d",&data);right = sizeof(arry)/sizeof(arry[0]);//求得总共有多少个元素ret = data_serch(arry,left,right,data);if(ret < 0)printf("No such number\n");if(ret >= 0)printf("在第%d个位置\n",ret+1);return 0;}