Submission #1371052

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 1e9+7;

ll n, dt[1000005], cur;

int main()
{
	scanf("%lld",&n);
	dt[0] = 1;
	dt[1] = n;
	dt[2] = n*n % mod;
	cur = 2*n-1;
	for(ll i=3;i<=n;i++) {
		cur += dt[i-1] - dt[i-2] + dt[i-3] - 1;
		cur = (cur%mod+mod)%mod;
		dt[i] = (cur + (n-1)*(n-1)) % mod;
	}
	printf("%lld\n",dt[n]);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:10:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&n);
                  ^

Judge Result