Submission #1440353

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;

const int maxn = 1000009;
const int MOD = 1e9+7;
LL f[maxn], n, sum;

int main(){
	scanf("%lld", &n);
	f[1] = n; f[2] = n*n%MOD;
	for (int i=3; i<=n; i++){
		f[i] = (f[i-1] + (n-1)*(n-1) + sum + (n-i+2)) % MOD;
		sum = (sum + f[i-2]) % MOD;
	}
	printf("%lld\n", f[n]);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:10:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &n);
                   ^

Judge Result