kuangbin_UnionFind A (POJ 2236)

挺接近模板的一题 接受O操作的时候扫一遍 符合条件的merge进去 done

#include <cstdio>
#include <cstring>
#include <cmath>

struct Point{float x,y;};
int father[1010];

float distance(Point a, Point b){
    return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}

int find(int x)
{
    while(father[x] != x)
        x = father[x];
    return x;
}

void merge(int x, int y)
{
    int tx = find(x);
    int ty = find(y);
    if(tx != ty)
        father[tx] = ty;
}

int main()
{
    Point p[1010];
    int n, d;
    bool open[1010];
    //initiate
    memset(open, false, sizeof open);
    for(int i = 1; i < 1010; i++)
        father[i] = i;
    //save cordinates
    scanf("%d%d", &n, &d);
    for(int i = 1; i <= n; i++)
        scanf("%f%f", &p[i].x, &p[i].y);
    //accept operations
    char tmp[2];
    while(scanf("%s",tmp)!=EOF)
    {
        if(tmp[0] == 'O'){
            int node;
            scanf("%d", &node);
            open[node] = true;
            for(int i = 1; i <= n; i++)
                if(open[i] && i != node)
                    if(distance(p[i], p[node]) <= (float)d){
                        //printf("distance(a,b) = %f
", distance(p[i], p[node]));
                        //printf("a = %d b = %d
", node, i);
                        merge(node, i);
                    }
        }
        else if (tmp[0] == 'S'){
            int a, b;
            scanf("%d%d",&a,&b);
            if(find(a) == find(b))
                puts("SUCCESS");
            else
                puts("FAIL");
        }
    }
    return 0;
}