【模板】二分查找

复制代码template <typename T>int binarySearch(T arr[],int n, T targrt){    int l = 0, r = n-1;  // arr[l ...  r]    while(l <= r){        //int mid = (l+r)/2;        int mid = l + (r-l)/2;        if(arr[mid] == targrt) return mid;        if(targrt < arr[mid]) r = mid - 1;        else l = mid + 1;    }    return -1;}