C# 二分查找代码

public class Solution {
    public int DistMoney(int money, int children) {
        if (money < children) return -1;
        money = money - children;
        int left = 0, right = children;
        while (left < right){
            int mid = left + right + 1 >> 1;
            if (Check(mid)) left = mid;
            else right = mid - 1;
        }

        return left;
        bool Check(int x){
            if (x * 7 > money) return false;
            if (x * 7 == money) return true;
            int t = money - x * 7;
            if (x == children - 1 && t == 3) return false;
            if (x == children && t > 0) return false;
            return true;
        }
    }
}

C# 模拟代码

public class Solution {
    public int DistMoney(int money, int children) {
        if (money < children) return -1;
        money -= children;
        int result = Math.Min(money / 7, children);
        money -= result * 7;
        children -= result;
        if ((children == 0 && money > 0) || (children == 1 && money == 3)) result--;
        return result;
    }
}