二分查找数组中与目标数字(可以是浮点型)最近的数的位置

 0 ///欢迎批评指正
 1 #include <stdio.h>

int a[100];

int search(int start,int end,double distinction){
    int mid;
    if(distinction > a[end - 1])
        return end - 1;
    if(distinction < a[start])
        return start;
    while(1){
        mid = (start + end) / 2;
        if(a[mid - 1] < distinction && a[mid] > distinction)
            return ((a[mid] - distinction) >= (distinction - a[mid - 1])) ? mid - 1 : mid;
        if(distinction > a[mid]){///(a[start] + a[end]) / 2.0 >
            start = mid;
        }else if(distinction < a[mid]){
            end = mid;
        }else{
            return mid;
        }
    }
}
int main(void){
    int n;
    double m;
    printf("输入数组元素个数：
");
    scanf("%d",&n);
    for(int i = 0; i < n; i++)
        scanf("%d",&a[i]);
    while(scanf("%lf",&m)!=0){
        printf("%d
",search(0,n,m));
    }

    return 0;
}