Submission #249422

#	Time	Username	Problem	Language	Result	Execution time	Memory
249422		thebes	parentrises (BOI18_parentrises)	C++14	100 / 100	211 ms	9348 KiB

parentrises

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

const int MN = 1e6+6, MM = 303, mod = 1e9+7;
int S, T, N, i, j, k, x, y, w[MN], cur, fl, ans[MM], dp[2][2*MM][2*MM];
string s; stack<int> go;
vector<pair<int,int>> qu;

int main(){
    scanf("%d",&S);
    if(S==1){
        scanf("%d",&T);
        while(T--){
            cin >> s; N = (int)s.size();
            for(i=0;i<N;i++) w[i]=1;
            while(go.size()) go.pop();
            cur = fl = 0;
            for(i=0;i<N;i++){
                if(s[i]=='('){
                    cur++;
                    go.push(i);
                }
                else if(cur) cur--;
                else{
                    if(go.empty()){
                        fl=1;
                        break;
                    }
                    w[go.top()]=2;
                    go.pop();
                }
            }
            while(go.size()) go.pop();
            cur = 0;
            for(i=N-1;i>=0;i--){
                if(s[i]==')'){
                    cur++;
                    go.push(i);
                }
                else if(cur>=w[i]) cur-=w[i];
                else{
                    int r = cur;
                    cur = 0;
                    while(r<w[i]){
                        if(go.empty()){
                            fl=1;
                            break;
                        }
                        r++;
                        w[go.top()]=2;
                        go.pop();
                    }
                }
            }
            if(fl) printf("impossible\n");
            else{
                int hm[]={0,0};
                for(i=0;i<N;i++){
                    if(w[i]==2) printf("G");
                    else{
                        int idx=s[i]=='('?0:1;
                        printf("%c","BR"[hm[idx]]), hm[idx]=!hm[idx];
                    }
                }
                printf("\n");
            }
        }
    }
    else{
        scanf("%d",&T);
        for(i=1;i<=T;i++){
            scanf("%d",&x);
            qu.push_back({x,i});
        }
        dp[0][0][0]=1;
        for(i=1;i<MM;i++){
            memset(dp[i&1],0,sizeof(dp[i&1]));
            for(j=0;j<2*MM;j++){
                for(k=0;k<2*MM;k++){
                    if(!dp[(i+1)&1][j][k]) continue;
                    dp[i&1][j+1][k+2]+=dp[(i+1)&1][j][k];
                    if(dp[i&1][j+1][k+2]>=mod) dp[i&1][j+1][k+2]-=mod;
                    int nj = max(0, j-2);
                    if(k){
                        dp[i&1][nj][k-1]+=dp[(i+1)&1][j][k];
                        if(dp[i&1][nj][k-1]>=mod) dp[i&1][nj][k-1]-=mod;
                    }
                }
            }
            int sna = 0;
            for(k=0;k<2*MM;k++){
                sna += dp[i&1][0][k];
                if(sna>=mod) sna-=mod;
            }
            for(auto v : qu){
                if(v.first==i) ans[v.second]=sna;
            }
        }
        for(i=1;i<=T;i++){
            printf("%d\n",ans[i]);
        }
    }
    return 0;
}

Compilation message (stderr)

parentrises.cpp: In function 'int main()':
parentrises.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&S);
     ~~~~~^~~~~~~~~
parentrises.cpp:12:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&T);
         ~~~~~^~~~~~~~~
parentrises.cpp:70:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&T);
         ~~~~~^~~~~~~~~
parentrises.cpp:72:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d",&x);
             ~~~~~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 6 / 6
• Subtask 4: 28 / 28
• Subtask 5: 6 / 6
• Subtask 6: 16 / 16
• Subtask 7: 28 / 28