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AcWing 194. 涂满它！

比完赛后补题解

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int N = 1e5 + 10, INF = 1e8;
int n, a[10][10], vis[10][10];
int dx[4] = {1, -1, 0, 0}, dy[4] = {0, 0, 1, -1};
int check()
{
    int cnt = 0, tot[6] = {0};
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (!tot[a[i][j]] && vis[i][j] != 1)
            {
                tot[a[i][j]] = 1;
                cnt++;
            }
        }
    }
    return cnt;
}
void paint(int x, int y, int color)
{
    vis[x][y] = 1;
    for (int i = 0; i < 4; i++)
    {
        int xx = x + dx[i], yy = y + dy[i];
        if (xx < 0 || xx >= n || yy < 0 || yy >= n || vis[xx][yy] == 1)
            continue;
        vis[xx][yy] = 2;
        if (a[xx][yy] == color)
            paint(xx, yy, color);
    }
}
int change(int color)
{
    int cnt = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
            if (a[i][j] == color && vis[i][j] == 2)
            {
                cnt++;
                paint(i, j, color);
            }
    }
    return cnt;
}
bool dfs(int dep, int cnt)
{
    if (cnt + check()> dep)
    {
        return 0;
    }
    if (!check())
        return 1;
    int back[10][10];
    for (int i = 0; i < 6; i++)
    {
        memcpy(back, vis, sizeof vis);
        if (change(i) && dfs(dep, cnt + 1))
            return 1;
        memcpy(vis, back, sizeof vis);
    }
    return 0;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    while (cin >> n && n)
    {
        memset(vis, 0, sizeof vis);
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                cin >> a[i][j];
        int dep = 0;
        paint(0, 0, a[0][0]);
        while (dep <= 50)
        {
            if (dfs(dep, 0))
                break;
            dep++;
        }
        cout << dep << '\n';
    }

    return 0;
}

标签：cnt,20,int,++,yy,vis,xx,2022.3
来源： https://www.cnblogs.com/menitrust/p/16031245.html