编辑代码

#include <iostream>  
using namespace std;  
void printArray(int array[], int arrLen) {
    for (int i = 0; i < arrLen; ++i) {
        cout << array[i] << " ";
    }
    cout << endl;
}

int FirstEqual(int searchKey, int array[], int arrLen) {
   int low = 0;
   int high = arrLen - 1;
   int keyPos = -1;

   while (low <= high) {
        int mid = low +((high - low + 1) >> 1);
        if (array[mid] > searchKey) {
            high = mid - 1;
        }
        else if (array[mid] < searchKey){
            low = mid + 1;
        }
        else {
            if (mid == 0 || array[mid - 1] != searchKey) {
                keyPos = mid;
                break;
            }
            else {
                high = mid - 1;
            }
        }
   }

   return keyPos;
}
int main(){
    int a[] = {1, 1, 2, 3, 4, 5, 6};
    int arrayLen = sizeof(a)/sizeof(int);

    printArray(a, arrayLen);
    cout << "第一个数组的位置："<< FirstEqual(6, a, arrayLen) << endl;
}