Bisect

Bisect_left

// all i < lo, arr[i] < x
int bisect_left(int arr, int x){
    int lo = 0, hi = arr.length, mid;
    while (lo < hi):
        mid = (lo+hi) / 2;
        if (a[mid] < x) lo = mid+1;
        else hi = mid;
    return lo;

}
    

Bisect_right

// all i >= lo, arr[i] > x
int bisect_left(int arr, int x){
    int lo = 0, hi = arr.length, mid;
    while (lo < hi):
        mid = (lo+hi) / 2;
        if (a[mid] > x) hi = mid;
        else lo = mid + 1;
    return lo;

}