Submission #74729

#	Time	Username	Problem	Language	Result	Execution time	Memory
74729		goodbaton	Linear Garden (IOI08_linear_garden)	C++14	100 / 100	380 ms	6776 KiB

linear_garden

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>

using namespace std;
typedef long long ll;

#define SIZE 1000010

int main(){
  int dp[2][5][5][5][2] = {};
  int n,m;
  char s[SIZE];
  
  scanf("%d%d%s",&n,&m,s);

  dp[0][2][2][2][0] = 1;
  
  for(int i=0;i<n;i++){

    for(int j=2;j<=4;j++){
      for(int k=j-2;k<=3;k++){
	for(int l=k;l<=j;l++){
	  dp[1-i%2][j][k][l][0] = 0;
	  dp[1-i%2][j][k][l][1] = 0;
	}
      }
    }

    for(int j=2;j<=4;j++){
      for(int k=j-2;k<=3;k++){
	for(int l=k;l<=j;l++){
	  int now_dp0 = dp[i%2][j][k][l][0]%m;
	  int now_dp1 = dp[i%2][j][k][l][1]%m;
	  
	  if(s[i]=='L'){
	    if(l>0 && j-(l-1) <= 2)
	      dp[1-i%2][j][min(k,l-1)][l-1][0] += now_dp0;
	  }else{
	    if(l>0 && j-(l-1) <= 2)
	      dp[1-i%2][j][min(k,l-1)][l-1][1] += now_dp0;
	    
	    if(l<4 && l+1-k <= 2)
	      dp[1-i%2][max(j,l+1)][k][l+1][0] += now_dp0;
	  }
	  
	  if(l>0 && j-(l-1) <= 2)
	    dp[1-i%2][j][min(k,l-1)][l-1][1] += now_dp1;
	    
	  if(l<4 && l+1-k <= 2)
	    dp[1-i%2][max(j,l+1)][k][l+1][1] += now_dp1;
	}
      }
    }
  }

  int ans = 0;
  
  for(int j=2;j<=4;j++){
    for(int k=j-2;k<=3;k++){
      for(int l=k;l<=j;l++){
	ans += dp[n%2][j][k][l][0];
	ans += dp[n%2][j][k][l][1];
      }
    }
  }
  
  
  printf("%d\n",ans%m);
}

Compilation message (stderr)

linear_garden.cpp: In function 'int main()':
linear_garden.cpp:16:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%s",&n,&m,s);
   ~~~~~^~~~~~~~~~~~~~~~~~

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