Submission #5929677

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
using LL  = long long;
using VI  = vector<LL>;
using VVI = vector<VI>;
using VB  = vector<bool>;
using VS  = vector<string>;
using PII = pair<LL, LL>;
using VP  = vector<PII>;
#define PB           push_back
#define MP           make_pair
#define SZ(a)        LL((a).size())
#define EACH(x, c)   for (auto x : (c))
#define ALL(c)       (c).begin(), (c).end()
#define REVERSE(c)   reverse(ALL(c))
#define SORT(c)      stable_sort(ALL(c))
#define RSORT(c)     stable_sort((c).rbegin(), (c).rend())
#define FSORT(c)     stable_sort(ALL(c), [] (auto& x, auto& y) {return x.first < y.first;});
#define FRSORT(c)    stable_sort(ALL(c), [] (auto& x, auto& y) {return x.first > y.first;});
#define SSORT(c)     stable_sort(ALL(c), [] (auto& x, auto& y) {return x.second < y.second;});
#define SRSORT(c)    stable_sort(ALL(c), [] (auto& x, auto& y) {return x.second > y.second;});
#define FOR(i, a, b) for (LL i = (a); i < (b); ++i)
#define REP(i, n)    FOR(i, 0, n)
#define $(x) {cout << #x << " = " << (x) << endl;}

int main() {
    LL N;
    cin >> N;
    VI plus, minus;
    REP(i, N) {
        LL a;
        cin >> a;
        if (a < 0) minus.PB(a);
        else plus.PB(a);
    }
    SORT(plus);
    RSORT(minus);

    VP trace;
    LL x, y;
    LL ans;
    LL mi = 0, pi = 0;
    if (SZ(minus) == 0) {
        trace.PB(MP(plus[0], plus[1]));
        ans = plus[0] - plus[1];
        if (N > 2) {
            for (LL i = 2; i < N - 1; ++i) {
                trace.PB(MP(ans, plus[i]));
                ans -= plus[i];
            }
            trace.PB(MP(plus[N - 1], ans));
            ans = plus[N - 1] - ans;
        }
    } else if (SZ(plus) == 0) {
        trace.PB(MP(minus[0], minus[1]));
        ans = minus[0] - minus[1];
        for (LL i = 2; i < N; ++i) {
            trace.PB(MP(ans, minus[i]));
            ans -= minus[i];
        }
    } else {
        ans = minus[0];
        for (LL i = 0; i < SZ(plus) - 1; ++i) {
            trace.PB(MP(ans, plus[i]));
            ans -= plus[i];
        }
        trace.PB(MP(plus[SZ(plus) - 1], ans));
        ans = plus[SZ(plus) - 1] - ans;
        for (LL i = 1; i < SZ(minus); ++i) {
            trace.PB(MP(ans, minus[i]));
            ans -= minus[i];
        }
    }

    cout << ans << endl;
    EACH(t, trace) {
        cout << t.first << " " << t.second << endl;
    }
	
    return 0;
}

Submission Info

Judge Result