#define 1e-8 eps

bool check(int/double x){
    ...
    for(...) ...
        if(...) return true/false;
    return false/true;
}

int bs_1(int l, int r){
    while(l < r){
        int mid = l + r >> 1;
        if(check(mid)) r = mid;
        else l = mid + 1;
    }
    return l;
}

int bs_2(int l, int r){
    while(l < r){
        int mid = l + r + 1 >> 1;
        if(check(mid)) l = mid;
        else r = mid - 1;
    }
    return l;
}

int bs_3(double l, double r){
    while(r - l > eps){
        int mid = (l + r) / 2;
        if(check(mid)) l = mid;
        else r = mid;
    }
    return l;
}