Peking University acm2236--wireless network~~ and check Collection

This question, the topic of the approximate meaning is: There are n computers, each other directly can communicate the maximum distance of T, these computers because of the earthquake damage, need to repair. After repair, you can communicate with other computers that have been repaired for less than or equal to T, and you need to answer whether the two computers can communicate.

Simple and check-set application, just add a limit condition.

Enter N and T, and the following n behaves n the coordinates of the computer.

The following is until the end of the file, enter O K, indicating that the K computer for repair. Enter S I j to ask if you can communicate with these two computers.

I use a dis array to save the distance between each of the two computers, which makes it easy to judge later.

The following is the AC code, with detailed comments:

#include <iostream> #include <cmath> #include <cstdio>using namespace std;double dis[1005][1005];                        The distance between each computer and other computers array int par[1005];                       and check set bool vis[1005]; Mark if the computer has been repaired int x[1005], y[1005];int N, T;int finds (int x)//and find function {if (x = = Par[x]) return X;elseret Urn Par[x] = finds (Par[x]);} void join (int x, int y)//And check-set merge function {x = finds (x); y = finds (y); if (x! = y) par[y] = x;} int main () {//freopen ("Data.txt", "R", stdin); int I, J, K, A, B;char str;scanf ("%d%d", &n, &t); for (i = 1; I <= N                             i++)//Enter each computer coordinate {scanf ("%d%d", &x[i], &y[i]);p ar[i] = i;                         Initialize and check set vis[i] = false; Marked as not repaired}getchar (); for (i = 1; I <= N; i++)//calculates the direct distance of each two computers {for (j = 1; J <= I and J + +) {if (i = = j) di S[I][J] = 0.0;elsedis[i][j] = dis[j][i] = sqrt (double ((X[i]-x[j]) + (X[i]-x[j]) * (Y[i]-y[j])));}} WhIle (scanf ("%c", &str)! = EOF) {if (str = = ' o ')//input is O, to be repaired {scanf ("%d", &k); GetChar (); for ( i = 1; I <= N;                i++)////with the repaired computer distance between the judge, determine whether can communicate {if (i! = k && vis[i] && dis[k][i] <= (double) T) {Join (I, k);                     Can be merged}}vis[k] = true;            Marked for repair over}else if (str = = ' S ')//To determine if communication {scanf ("%d%d", &a, &b) is possible, GetChar (), if (finds (a) = = finds (b)) belong to the same and check set, you can printf ("success\n"); elseprintf ("fail\n");}} return 0;}

Peking University acm2236--wireless network~~ and check Collection