Submission #301591

#	Time	Username	Problem	Language	Result	Execution time	Memory
301591		kevinsogo	Handcrafted Gift (IOI20_gift)	C++17	100 / 100	190 ms	17020 KiB

gift

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

int construct(int n, int r, vector<int> a, vector<int> b, vector<int> x) {
    vector<int> same(n);
    for (int i = 0; i < r; i++) {
        if (x[i] == 1) {
            same[a[i]]++;
            same[b[i]]--;
        }
    }
    for (int i = 0; i < n - 1; i++) same[i + 1] += same[i];
    assert(same.back() == 0);
    vector<int> diff(n);
    for (int i = 0; i < n - 1; i++) diff[i + 1] = diff[i] + !same[i];
    for (int i = 0; i < r; i++) {
        if (x[i] == 1) assert(diff[a[i]] == diff[b[i]]);
        if (x[i] == 2 && diff[a[i]] == diff[b[i]]) return 0;
    }

    string s(n, 'R');
    for (int i = 0; i < n - 1; i++) {
        s[i + 1] = s[i] ^ (!same[i] * ('R' ^ 'B'));
    }
    craft(s);
    return 1;
}

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