Submission #525670

#	Time	Username	Problem	Language	Result	Execution time	Memory
525670		tatyam	Handcrafted Gift (IOI20_gift)	C++17	100 / 100	143 ms	22672 KiB

gift

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

void craft(string &s);

int construct(int n, int r, vector<int> a, vector<int> b, vector<int> x){
    vector<int> imos(n);
    for(int i = 0; i < r; i++) if(x[i] == 1){
        imos[a[i]]++;
        imos[b[i]]--;
    }
    for(int i = 0; i < n - 1; i++) imos[i + 1] += imos[i];
    imos.pop_back();
    for(int& x : imos) x = !x;
    string s(n, 'R');
    for(int i = 0; i < n - 1; i++){
        if(imos[i])  s[i + 1] = s[i] ^ 'R' ^ 'B';
        else s[i + 1] = s[i];
    }
    imos.insert(imos.begin(), 0);
    for(int i = 0; i < n - 1; i++) imos[i + 1] += imos[i];
    for(int i = 0; i < r; i++) if(x[i] == 2){
        if(imos[a[i]] == imos[b[i]]) return 0;
    }
    craft(s);
    return 1;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30