Submission #548357

#	Time	Username	Problem	Language	Result	Execution time	Memory
548357		krit3379	Kangaroo (CEOI16_kangaroo)	C++17	0 / 100	0 ms	340 KiB

kangaroo

#include<bits/stdc++.h>
using namespace std;
#define N 205

int a[N][N][N],d[N][N][N],mod=1e9+7;

int main(){
    int n,s,e,i,j,k,l;
    scanf("%d %d %d",&n,&s,&e);
    if(n==2){
        printf("1");
        return 0;
    }
    a[2][1][2]=1;
    d[2][2][1]=1;
    for(i=3;i<=n;i++){
        for(j=1;j<=i;j++){
            for(k=1;k<=i;k++){
                if(j==k){
                    a[i][j][k]=(a[i][j][k]+a[i][j-1][k])%mod;
                    d[i][j][k]=(d[i][j][k]+d[i][j-1][k])%mod;
                    continue;
                }
                a[i][j][k]=(d[i-1][i-1][k-(j<k)]-d[i-1][j-1][k-(j<k)])%mod;
                if(j<k)a[i][j][k]=(a[i][j][k]-(d[i-1][k-1][k-(j<k)]-(k>1)?d[i-1][k-2][k-(j<k)]:0)%mod+mod)%mod;
                d[i][j][k]=a[i-1][j-1][k-(j<k)];
                if(j>k)d[i][j][k]=(d[i][j][k]-(a[i-1][k][k-(j<k)]-a[i-1][k-1][k-(j<k)])%mod+mod)%mod;
                if(i==n&&j==s&&k==e){
                    printf("%d",(a[i][j][k]+d[i][j][k])%mod);
                  	return 0;
                }
                a[i][j][k]=(a[i][j][k]+a[i][j-1][k])%mod;
                d[i][j][k]=(d[i][j][k]+d[i][j-1][k])%mod;
            }
        }
    }
    return 0;
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:8:21: warning: unused variable 'l' [-Wunused-variable]
    8 |     int n,s,e,i,j,k,l;
      |                     ^
kangaroo.cpp:9:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |     scanf("%d %d %d",&n,&s,&e);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49