Submission #527788

#	Time	Username	Problem	Language	Result	Execution time	Memory
527788		boris_mihov	Diamond Hands (innopolis2021_final_B)	C++14	16 / 100	39 ms	2000 KiB

Main

#include <iostream>
#include <vector>
#include <cassert>
const int maxn = 2e5+10;

int n;
std::pair < int, int > d[maxn];
std::vector < std::pair < int, char > > ans;

void invalid() {

    std::cout << -1 << '\n';
    exit(0);

}

void solve() {

    for (int i = 1 ; i <= n ; ++i) {

        int diff = d[i].first - d[i-1].first;
        int desired = d[i].second - d[i-1].second;
        if (!(-diff <= desired && desired <= diff && (diff - desired) % 2 == 0)) invalid();

        if (desired == diff) {

            // if (i == 2 && ans.size() == 2) swap(ans.front(), ans.back());
            if (!ans.empty() && ans.back().second == '+') ans.back().first += diff;
            else ans.push_back({diff, '+'});
            continue;

        }

        if (desired == -diff) {

            if (!ans.empty() && ans.back().second == '-') ans.back().first += diff;
            else ans.push_back({diff, '-'}); 
            continue;          

        }

        int subtract = (diff - desired) / 2;
        int add = diff - subtract;

        if (i == 1) {

            ans.push_back({add, '+'});
            ans.push_back({subtract, '-'});
            continue;

        }

        if (ans.back().second == '+') {

            ans.back().first += add;
            ans.push_back({subtract, '-'});
            continue;

        }

        ans.back().first += subtract;
        ans.push_back({add, '+'});

    }

    std::cout << ans.size() << '\n';
    for (int i = 0 ; i < ans.size() ; ++i)
        std::cout << ans[i].first << ' ' << ans[i].second << '\n';

    for (int i = 0 ; i < ans.size()-1 ; ++i)
        assert(ans[i].second != ans[i+1].second);

}

void read() {

    std::cin >> n;
    for (int i = 1 ; i <= n ; ++i)
        std::cin >> d[i].first >> d[i].second;

}

void fast_io() {

    std::ios_base :: sync_with_stdio(0);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);

}

int t;
int main () {

    fast_io();
    read();
    solve();

    return 0;

}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:67:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for (int i = 0 ; i < ans.size() ; ++i)
      |                      ~~^~~~~~~~~~~~
Main.cpp:70:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for (int i = 0 ; i < ans.size()-1 ; ++i)
      |                      ~~^~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 8
• Subtask 3: 10 / 10
• Subtask 4: 0 / 28
• Subtask 5: 0 / 17
• Subtask 6: 0 / 31