求助大佬

AT1198_100 @ 2020-04-01 15:09:44

#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
int main(){
    int n,x;
    cin>>x;
    n=sqrt(2*x+1/4)-1/2;
    cout<<(n*(n+1)*(2*n+1))/6;
    return 0;
}

by 化身灵蝶子 @ 2020-05-01 16:41:35

# include <stdio.h>

int main()

{

   int i, j, k,t=0,x=0,coin=0;
    int  a[100000];

    scanf_s("%d", &k);

    for (i =0; i <= 200; i++)

    {

        j = i;

        for (j; j > 0; j--)

        {

            a[t] = i;

            t++;

        }

    }

    for (x = 0; x < k; x++)

    {

        coin += a[x];

    }

    printf("%d", coin);

        return 0;

}