Submission #651395

#	Time	Username	Problem	Language	Result	Execution time	Memory
651395		Alan	Handcrafted Gift (IOI20_gift)	C++17	100 / 100	220 ms	24596 KiB

gift

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

int construct(int n, int m, vector<int> a, vector<int> b, vector<int> x) {
    string s (n, 0);
	vector<int> d (n+1), ps (n+1);
	for (int i = 0; i < m; i++) if (x[i] == 1) {
		d[a[i]]++;
		d[b[i]+1]--;
	}
	bool r = true;
	for (int i = 0; i < n; i++) {
		if (i) d[i] += d[i-1];
		if (!d[i] || (i && !d[i-1])) r = !r;
		s[i] = r ? 'R' : 'B';
		ps[i] += s[i] == 'B';
		if (i) ps[i] += ps[i-1];
	}
	for (int i = 0; i < m; i++) if (x[i] == 2) {
		int diff = ps[b[i]] - (a[i] ? ps[a[i]-1] : 0);
		if (diff == 0 || diff == b[i]-a[i]+1) 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