python/TangDou/XiTi/1062.cpp

#include <bits/stdc++.h>

using namespace std;
int k;       //第k天付出多少个金币
int coin;    //多少个金币
int day = 1; //现在是第几天
int main() {
    cin >> k;
    for (int i = 1;; i++) {            //此层循环描述的是第几轮
        for (int j = 1; j <= i; j++) { //此层循环描述是当前轮的第几天
            //金币数增加p个(轮次号个)
            coin += i;
            if (day == k) {
                cout << coin << endl;
                return 0;
            }
            day++;
        }
    }
    return 0;
}