贪心算法解决地图着色问题代码

根据提供的引用内容，以下是使用贪心算法解决地图着色问题的代码：

#include <iostream>
#include <cstring>
using namespace std;

const int MAXN = 1005;
int n, m, ans;
int color[MAXN], arc[MAXN][MAXN];

bool OK(int i) {
    for (int j = 0; j < n; j++) {
        if (arc[i][j] == 1 && color[i] == color[j]) {
            return false;
        }
    }
    return true;
}

void colorgraph() {
    int k = 0, flag = 1;
    while (flag == 1) {
        k++;
        flag = 0;
        for (int i = 0; i < n; i++) {
            if (color[i] == 0) {
                color[i] = k;
                if (!OK(i)) {
                    color[i] = 0;
                    flag = 1;
                }
            }
        }
    }
    ans = k;
}

int main() {
    cin >> n >> m;
    memset(arc, 0, sizeof(arc));
    memset(color, 0, sizeof(color));
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        arc[u][v] = arc[v][u] = 1;
    }
    colorgraph();
    cout << "最小色数为：" << ans << endl;
    cout << "各顶点的颜色为：";
    for (int i = 0; i < n; i++) {
        cout << color[i] << " ";
    }
    cout << endl;
    return 0;
}