#include<iostream>#include<stdlib.h>#include <math.h>using namespace std;float a[] = {1.2, 2.6, 3.4, 4.2, 5.5, 6.7, 7.1, 8.5, 9.8, 9.9};int main() {    int n = sizeof(a)/sizeof(int);    float f;    cout << "Please input the number:" << endl;    cin >> f;    int low = 0;    int high = n - 1;    int mid;    int index;    float diff, diff_l, diff_r;    while(low <= high) {        int flag1 = 0;        int flag2 = 0;        mid = low + (high - low)/2;        diff = (a[mid] - f) > 0 ? (a[mid] - f) : (f - a[mid]);        if(mid - 1 >= low ) {            diff_l = (a[mid - 1] - f) > 0 ? (a[mid - 1] - f) : (f -a[mid - 1]) ;            flag1 = 1;        }        if(mid + 1 <= high){            diff_r = (a[mid + 1] - f) > 0 ? (a[mid + 1] -f) : (f - a[mid + 1]);            flag2 = 1;        }        if(flag1 == 1 && flag2 == 1)        {            if (diff_l >= diff && diff_r >= diff) {                index = mid;                break;            }             if (diff_l < diff_r) {                high = mid - 1;            } else {                low = mid + 1;            }        } else if(flag1 == 1) {            if(diff_l >= diff) {                index = mid ;                break;            } else {                high = mid - 1;            }        } else if(flag2 == 1) {            if (diff_r >= diff) {                index = mid;                break;            } else {                low = mid + 1;            }        } else {            index  = mid;            break;        }    }    cout << index << endl;    return 0;}