【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;
}