Wqs二分

Luogu P2619 [国家集训队]Tree I

Luogu P5633 最小度限制生成树

CF802O April Fools’ Problem (hard)

int WqsDic() {
    int L = -MAXw, R = MAXw, M;
    int ans, chosea;
    while (L < R) {
        M = (L + R + 1) >> 1;
        Check(M, ans, chosea);
        if (chosea > need) {
            L = M;
        } else if (chosea < need) {
            R = M - 1;
        } else {
            return ans;
        }
    }
    Check(L, ans, chosea);
    return ans;
}