Submission #1088706

#	Time	Username	Problem	Language	Result	Execution time	Memory
1088706		Sunbae	Kangaroo (CEOI16_kangaroo)	C++17	100 / 100	33 ms	31680 KiB

kangaroo

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
const ll mod = 1e9 + 7;
ll dp[2001][2001];
signed main(){
	int n, s, e; scanf("%d %d %d", &n, &s, &e);
	dp[1][1] = 1;
	for(int i = 2; i<=n; ++i){
		for(int j = 1; j<=n; ++j){
			if(i == s || i == e){
				dp[i][j] = (dp[i-1][j] + dp[i-1][j-1]) % mod; 
			}else{
				dp[i][j] = (dp[i][j] + (dp[i-1][j+1] * j) % mod ) % mod;
				dp[i][j] = (dp[i][j] + (dp[i-1][j-1] * max((j-(s<i)-(e<i)), 0)) % mod )  % mod;
		}
		}
	}
	printf("%lld", dp[n][1]);
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:7:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    7 |  int n, s, e; scanf("%d %d %d", &n, &s, &e);
      |               ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 30 / 30
• Subtask 3: 15 / 15
• Subtask 4: 49 / 49