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답안 #136163

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
136163 2019-07-24T20:38:58 Z dragonslayerit 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 39 ms 15996 KB 
#include <cstdio>

const int MOD=1e9+7;

int dp[2001][2001];//index,#ccs

void addmod(int& x,long long y){
  x=(x+y)%MOD;
}

int main(){
  int N,S,T;
  scanf("%d %d %d",&N,&S,&T);
  S--,T--;
  dp[0][0]=1;
  for(int i=0;i<N;i++){
    if(i==S||i==T){
      for(int cc=0;cc<N;cc++){
	if(cc) addmod(dp[i+1][cc],dp[i][cc]);
	addmod(dp[i+1][cc+1],dp[i][cc]);
      }
    }else{
      for(int cc=0;cc<N;cc++){
	addmod(dp[i+1][cc+1],dp[i][cc]*1LL*(cc+1-(i>S)-(i>T)));
	if(cc>0) addmod(dp[i+1][cc-1],dp[i][cc]*1LL*(cc-1));
      }
    }
  }
  printf("%d\n",dp[N][1]);
}

Compilation message

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d",&N,&S,&T);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 504 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 504 KB Output is correct
9 Correct 2 ms 504 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 504 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 504 KB Output is correct
9 Correct 2 ms 504 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 3 ms 1272 KB Output is correct
13 Correct 3 ms 1144 KB Output is correct
14 Correct 3 ms 1272 KB Output is correct
15 Correct 3 ms 1272 KB Output is correct
16 Correct 3 ms 1272 KB Output is correct
17 Correct 3 ms 1276 KB Output is correct
18 Correct 3 ms 1144 KB Output is correct
19 Correct 4 ms 1272 KB Output is correct
20 Correct 3 ms 1272 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 504 KB Output is correct
5 Correct 2 ms 504 KB Output is correct
6 Correct 2 ms 504 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 504 KB Output is correct
9 Correct 2 ms 504 KB Output is correct
10 Correct 2 ms 504 KB Output is correct
11 Correct 2 ms 504 KB Output is correct
12 Correct 3 ms 1272 KB Output is correct
13 Correct 3 ms 1144 KB Output is correct
14 Correct 3 ms 1272 KB Output is correct
15 Correct 3 ms 1272 KB Output is correct
16 Correct 3 ms 1272 KB Output is correct
17 Correct 3 ms 1276 KB Output is correct
18 Correct 3 ms 1144 KB Output is correct
19 Correct 4 ms 1272 KB Output is correct
20 Correct 3 ms 1272 KB Output is correct
21 Correct 9 ms 4728 KB Output is correct
22 Correct 9 ms 4984 KB Output is correct
23 Correct 11 ms 5624 KB Output is correct
24 Correct 39 ms 15992 KB Output is correct
25 Correct 39 ms 15996 KB Output is correct
26 Correct 39 ms 15992 KB Output is correct
27 Correct 39 ms 15864 KB Output is correct
28 Correct 28 ms 12084 KB Output is correct