05-树7. File Transfer

We have a network of computers and a list of bi-directional connections. Each of these connections allows a file transfer from one computer to another. Is it possible to send a file from any computer on the network to any other?

Input Specification:

Each input file contains one test case. For each test case, the first line contains N (2<=N<=104), the total number of computers in a network. Each computer in the network is then represented by a positive integer between 1 and N. Then in the following lines, the input is given in the format:
I c1 c2

where I stands for inputting a connection between c1 and c2; or
C c1 c2

where C stands for checking if it is possible to transfer files between c1 and c2; or
S

where S stands for stopping this case.

Output Specification:

For each C case, print in one line the word “yes” or “no” if it is possible or impossible to transfer files between c1 and c2, respectively. At the end of each case, print in one line “The network is connected.” if there is a path between any pair of computers; or “There are k components.” where k is the number of connected components in this network.
Sample Input 1:5
C 3 2
I 3 2
C 1 5
I 4 5
I 2 4
C 3 5
S

Sample Output 1:no
no
yes
There are 2 components.

Sample Input 2:5
C 3 2
I 3 2
C 1 5
I 4 5
I 2 4
C 3 5
I 1 3
C 1 5
S

Sample Output 2:no
no
yes
yes
The network is connected.
简单的并查集的题目，但是要注意建树的时候把小的树挂在大的树上降低树的高度。这样才不会超时。

#include<stdio.h>#include<stdlib.h>typedef struct {    int data;    int parent;}SetType;int cmp(SetType p[],int size,int x1,int x2);int find(SetType p[],int size,int x);void Union(SetType p[],int size,int x1,int x2);int main(){    int N,i,m,n,sum = 0;    SetType setType[10001];    scanf("%d",&N);    for(i = 0;i<N;i++){        setType[i].data = i+1;        setType[i].parent = -1;    }    char key;    scanf("%c",&key);    while(key!='S'){        if(key == 'C'){            scanf("%d %d",&m,&n);            if(cmp(setType,N,m,n))                printf("yes\n");            else                printf("no\n");            getchar();        }        if(key == 'I'){            scanf("%d %d",&m,&n);            Union(setType,N,m,n);        }        scanf("%c",&key);    }    for(i = 0;i<N;i++){        if(setType[i].parent < 0)            sum++;    }    if(1 == sum)        printf("The network is connected.");    else        printf("There are %d components.",sum);    return 0;}int cmp(SetType p[],int size,int x1,int x2){    int root1,root2;    if(x1 == x2)        return 1;    root1 = find(p,size,x1);    root2 = find(p,size,x2);    if(root1 == root2)        return 1;    else        return 0;}//   查 int find(SetType p[],int size,int x){    int i = x-1;    if(i>=size)        return -1;    for(;p[i].parent>=0;i = p[i].parent);    return i;}//  并 void Union(SetType p[],int size,int x1,int x2){    int root1,root2;    root1 = find(p,size,x1);    root2 = find(p,size,x2);    if(root1!=root2){        if(p[root1].parent<p[root2].parent){            p[root1].parent += p[root2].parent;            p[root2].parent = root1;        }        else{            p[root2].parent += p[root1].parent;            p[root1].parent = root2;        }    }}