Submission #578970

#	Time	Username	Problem	Language	Result	Execution time	Memory
578970		FatihSolak	parentrises (BOI18_parentrises)	C++17	100 / 100	631 ms	7428 KiB

parentrises

#include <bits/stdc++.h>
#define N 305
using namespace std;
const int mod = 1e9 + 7;
int val[N];
int val2[N];
int ans[N];
void solve1(){
    string s;
    cin >> s;
    int n = s.size();
    vector<int> r,rr,points;
    string ans = "";
    int a = 0,b = 0;
    for(int i = 0;i<n;i++){
        ans += ".";
        if(s[i] == '(')a++;
        else b++;
        if(2*a < b){
            cout << "impossible" << endl;
            return;
        }
        if(s[i]  == '('){
            ans[i] = 'R';
            r.push_back(i);
            rr.push_back(i);
        }
        if(s[i] == ')'){
            if(rr.empty()){
                ans[r.back()] = 'G';
                ans[i] = 'B';
                r.pop_back();
                continue;
            }
            rr.pop_back();
            points.push_back(i);
            ans[i] = 'R';
        }
    }
    if(2*b < a){
        cout << "impossible" << endl;
        return;
    }
    for(int i = 0;i<rr.size();i++){
        ans[rr[i]] = 'B';
        ans[points[points.size() - rr.size() + i]] = 'G';
        if(rr[i] > points[points.size() - rr.size() + i]){
            cout << "impossible" << endl;
            return;
        }
    }
    cout << ans << endl;
}
void solve2(){
    int n;
    cin >> n;
    cout << (ans[n] + val[n])%mod  << endl;
}
int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    #endif
    for(int i = 0;i*3<N;i++){
        int a = i,b = 2*i;
        vector<vector<int>> dp(N,vector<int>(N,0));
        dp[0][0] = 1;
        for(int i = 0;i<N;i++){
            for(int j = 0;j<N;j++){
                bool ok = 1;
                if(2*(i+1) < j)
                    ok = 0;
                if(i + 1 > a)
                    ok = 0;
                if(ok){
                    dp[i+1][j] = (dp[i+1][j] + dp[i][j])%mod;
                }
                ok = 1;
                if(2*i < j+1)
                    ok = 0;
                if(j + 1 > b)
                    ok = 0;
                if(ok){
                    dp[i][j+1] = (dp[i][j+1] + dp[i][j])%mod;
                }
            }
        }
        //cout << dp[a][b] << endl;
        val[3*i] = dp[a][b];
    }
    //for(int a = 1;a<N;a++){
    //    for(int b = 1;b<2*a && b + a < N;b++){
    for(int num = -(N-1);num < 2*(N-1);num++){
        vector<vector<int>> dp(N,vector<int>(N,0));
        dp[0][1] = 1;
        for(int i = 0;i<N;i++){
            for(int j = 1;j<N;j++){
                bool ok = 1;
                if(i == 2*j)
                    ok = 0;
                if(num <= 2*i-j)
                    ok = 0;
                if(i + 1 == N)
                    ok = 0;
                if(ok){
                    dp[i+1][j] = (dp[i+1][j] + dp[i][j])%mod;
                }
                ok = 1;
                if(num <= 2*i-j)
                    ok = 0;
                if(j + 1 == N)
                    ok = 0;
                if(ok){
                    dp[i][j+1] = (dp[i][j+1] + dp[i][j])%mod;
                }

            }
        }
        for(int i = 0;i<N;i++){
            for(int j = 0;j<N;j++){
                if(2*i - j == num && i+j < N && 2*i > j && 2*j >= i){
                    val2[i+j] = (val2[i+j] + dp[i][j])%mod;
                }
            }
        }
    }
    for(int i = 1;i<N;i++){
        for(int j = 0;j<N;j++){
            ans[i+j] = (ans[i+j] + (long long)val2[i]*val[j])%mod;
        }
    }
    int type;
    cin >> type;
    int t=1;
    cin>>t;
    while(t--){
        if(type == 1)
            solve1();
        if(type ==2)
            solve2();
    }
    #ifdef Local
    cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

Compilation message (stderr)

parentrises.cpp: In function 'void solve1()':
parentrises.cpp:44:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for(int i = 0;i<rr.size();i++){
      |                   ~^~~~~~~~~~
parentrises.cpp: In function 'int32_t main()':
parentrises.cpp:131:32: warning: iteration 304 invokes undefined behavior [-Waggressive-loop-optimizations]
  131 |             ans[i+j] = (ans[i+j] + (long long)val2[i]*val[j])%mod;
      |                         ~~~~~~~^
parentrises.cpp:130:24: note: within this loop
  130 |         for(int j = 0;j<N;j++){
      |                        ^

• 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