Cứuuuuuuuuuuuuu

Làm Bằng C++ nha!

Hint 1: dùng vòng lặp

#include <bits/stdc++.h>

using namespace std;

long long n, s = 0;
int main() {
 cin >> n;   
 for (long long i = 1; i <= n; ++i) s += (i * i * i);
 cout << s;
 return 0;
}

Hint 2: dùng công thức (hiệu quả hơn lặp)

#include <bits/stdc++.h>

using namespace std;

long long n;
int main() {
 cin >> n;  
 cout << (n * n * (n + 1) * (n + 1)) / 4;
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
#define int long long 

signed main(){
	int n;
	cin>>n;
	int ans=0;
	for(int i=1;i<=n;i++){
		ans+=i*i*i;
	}
	cout<<ans;
	//Cach 1: For
	//Author:jixght
}

#include <bits/stdc++.h>
using namespace std;
#define int long long 

signed main(){
	int n;
	cin>>n;
	int ans=n*(n+1)/2;
	cout<<ans*ans;
	//Cach 2: Cong thuc
	//Author:jixght
}