星空之夜

具体代码：

#include<iostream>
#include<cmath>
#include<algorithm>
#include<cstring>
#define x first
#define y second
#define N 110
#define esq 1e-6
using namespace std;

typedef pair<int,int> PII;

char g[N][N];   //地图
PII q[N*N];     //存放连通块
int top;        //指向q数组
int h,w;

void dfs(int a,int b)
{
    q[top++] = {a,b};
    g[a][b] = 0;
    for(int x = a - 1;x <= a + 1;x ++)
        for(int y = b - 1;y <= b + 1;y ++)
        {
            if(x == a && y == b)    continue;
            if(x >= 0 && x < h && y >= 0 && y < w && g[x][y] == '1')
                dfs(x,y);
        }
}

double get_dist(PII a,PII b)
{
    double dx = a.x - b.x;
    double dy = a.y - b.y;
    return sqrt(dx*dx + dy*dy);
}

double get_hash()
{
    double sum = 0;
    for(int i = 0;i < top;i ++)
        for(int j = 0;j < top;j ++)
            sum += get_dist(q[i],q[j]);
    return sum;
}

char get_id(double key)
{
    static double hash[30];
    static int id = 0;
    for(int i = 0;i < id;i ++)
        if(fabs(hash[i] - key) < esq)
            return i + 'a';
    hash[id++] = key;
    return id - 1 + 'a';
}

int main()
{
    cin>>w>>h;

    for(int i = 0;i < h;i ++)   cin>>g[i];

    for(int i = 0;i < h;i ++)
        for(int j = 0;j < w;j ++)
            if(g[i][j] == '1')
            {
                top = 0;
                dfs(i,j);
                char c = get_id(get_hash());
                for(int k = 0;k < top;k ++)
                    g[q[k].x][q[k].y] = c;
            }
    for(int i = 0;i < h;i ++)   cout<<g[i]<<endl;
}