Lang:G++
Edit12345678910111213141516171819202122232425262728293031#include<iostream>#include<cstdio>#include<cstring>using namespace std;typedef long long ll;const ll MOD=1e9+7;int dp[100010][5][5];int n;void init(){memset(dp,0,sizeof(dp));dp[0][0][0]=1;for(int i=1;i<=1e5;i++){for(int j=0;j<2;j++){for(int k=0;k<3;k++){dp[i][j][0]=(dp[i][j][0]+dp[i-1][j][k])%MOD;if(j) dp[i][j][0]=(dp[i][j][0]+dp[i-1][j-1][k])%MOD;if(k) dp[i][j][k]=(dp[i][j][k]+dp[i-1][j][k-1])%MOD;}}}}int main(){init();while(cin>>n){ll ans=0;for(int j=0;j<2;j++){for(int k=0;k<3;k++){