C语言习题006:二分(折半)查找

#include <stdio.h>

int rank(int array[],int size,int elment){
    int start=0;
    int last=size-1;
    while (start<=last) {
        int mid=start+(last-start)/2;
        if (elment<array[mid]) {
            last=mid-1;
        }
        else if(elment>array[mid]){
            start=start+1;
        }
        else{
            return mid;
        }
    }
    return -1;
}

int main(){
    int array[]={4,20,43,54,60,66};
    int elment;
    scanf("%d",&elment);
    int size=sizeof(array)/sizeof(array[0]);
    int result=rank(array,size,elment);
    printf("%d\n",result);
    return 0;
}