Submission #306835

#	Time	Username	Problem	Language	Result	Execution time	Memory
306835		joylintp	Handcrafted Gift (IOI20_gift)	C++14	10 / 100	277 ms	16992 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<pair<int, int>> v;
    for (int i = 0; i < r; i++)
        if (x[i] == 1)
            v.push_back({a[i], b[i]});
    sort(v.begin(), v.end());

    vector<pair<int, int>> same;
    for (int i = 0; i < v.size(); i++)
        if (same.empty())
            same.push_back(v[i]);
        else if (same.back().second >= v[i].first)
            same.back().second = max(same.back().second, v[i].second);
        else
            same.push_back(v[i]);

    string s(n, '_');
    for (auto p : same)
        for (int i = p.first; i <= p.second; i++)
            s[i] = 'R';

    for (int i = 0; i < n; )
        if (s[i] == '_')
        {
            int j = i;
            while (j < n && s[j] == '_')
                s[j] = "BR"[(j - i) % 2];
            i = j;
        }
        else
            i++;

    vector<int> v2;
    for (auto p : same)
        v2.push_back(p.first), v2.push_back(p.second);

    for (int i = 0; i < r; i++)
    {
        if (x[i] == 1)
            continue;

        if (a[i] == b[i])
            return 0;

        int pos = lower_bound(v2.begin(), v2.end(), a[i]) - v2.begin();
        if (pos < v2.size() && pos % 2 == 0 && b[i] <= v2[pos + 1])
            return 0;
    }

    craft(s);
    return 1;
}

Compilation message (stderr)

gift.cpp: In function 'int construct(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
gift.cpp:14:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     for (int i = 0; i < v.size(); i++)
      |                     ~~^~~~~~~~~~
gift.cpp:51:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |         if (pos < v2.size() && pos % 2 == 0 && b[i] <= v2[pos + 1])
      |             ~~~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 20
• Subtask 4: 0 / 25
• Subtask 5: 0 / 30