abc081d <思维 构造>

标签：cout int 情况 abc081d using include

D - Non-decreasing

// https://atcoder.jp/contests/abc081/tasks/arc086_b
// <思维 构造>
// 两种情况非常容易构造 : 全整数情况 & 全负数情况, 仅需顺序累加即可
// 将其他情况转变为以上两种情况 : 
//  找到n个数中的最大值 a[r] 和 最小值 a[l], 
//  根据情况将所有数加上最大值或最小值, 使得转变为全正或全负情况
#include <iostream>
#include <algorithm>
#include <vector>
#include <cstring>
#include <random>
using namespace std;
using LL = long long;
using PII = pair<int, int>;
const int N = 60;
int a[N];

void solv()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    int l = min_element(a+1, a+1+n) - a;
    int r = max_element(a+1, a+1+n) - a;
    cout << 2*n-1 << endl;
    if (a[l] + a[r] >= 0)
    {
        for (int i = 1; i <= n; i ++) cout << r << ' ' << i << endl;
        for (int i = 1; i < n; i ++) cout << i << ' ' << i+1 << endl;
    }
    else
    {
        for (int i = 1; i <= n; i ++) cout << l << ' ' << i << endl;
        for (int i = n; i > 1; i --) cout << i << ' ' << i-1 << endl;
    }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    // cin >> T;
    while (T--)
    {
        solv();
    }
    return 0;
}

标签：cout,int,情况,abc081d,using,include
From： https://www.cnblogs.com/o2iginal/p/17546938.html