[CF349B] Color the Fence

[CF349B] Color the Fence - 贪心

Description

写每个数字会花费一定油漆 ai，没有数字 0，只有 v 升油漆，问能写出的最大数字是多少。

Solution

首先我们肯定会最大化数字的长度

然后我们会从前到后依次最大化数字，即试图让第一个数字取最大，然后……

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

#define int long long

const int N = 1000005;

int a[N], s[N], v;

signed main()
{
    ios::sync_with_stdio(false);

    cin >> v;
    for (int i = 1; i <= 9; i++)
        cin >> a[i];

    int min_value = 1e9, min_id = 0;
    for (int i = 1; i <= 9; i++)
    {
        if (a[i] <= min_value)
        {
            min_value = a[i];
            min_id = i;
        }
    }

    int len = 0;
    while (v >= min_value)
    {
        s[++len] = min_id;
        v -= min_value;
    }

    for (int i = 1; i <= len; i++)
    {
        int max_id = 0;
        for (int j = min_id + 1; j <= 9; j++)
        {
            if (a[j] > min_value && a[j] - min_value <= v)
                max_id = j;
        }
        if (max_id)
        {
            v -= a[max_id] - min_value;
            s[i] = max_id;
        }
        cout << s[i];
    }

    if (len == 0)
        cout << -1;
}