05-樹8 File Transfer (25分)

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 containsN(2), the total number of computers in a network. Each computer in the network is then represented by a positive integer between 1 andN. Then in the following lines, the input is given in the format:

I c1 c2  

whereIstands for inputting a connection betweenc1andc2; or

C c1 c2   

whereCstands for checking if it is possible to transfer files betweenc1andc2; or

S 

whereSstands for stopping this case.

Output Specification:

For eachCcase, print in one line the word "yes" or "no" if it is possible or impossible to transfer files betweenc1

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.

提交測試程式碼：

#include <stdio.h>
#include <stdlib.h>
#define MAXSIZE 10000
typedef int ElementType;
typedef int SetName;
typedef ElementType SetType[MAXSIZE];
SetName Find(SetType S, ElementType X){
    for(;S[X]>=0; X=S[X]);
    return X;
}
/*按秩歸併的兩種實現*/
//按樹高歸併
//void Union(SetType S, SetName Root1, SetName Root2){
//    if(S[Root2] < S[Root1]){
//        S[Root1] = Root2;
//    }
//    else{
//       if(S[Root1] == S[Roo2]) S[Root1]++;
//        S[Root2] = Root1;
//    }
//}

//按規模（元素個數）歸併
void Union(SetType S, SetName Root1, SetName Root2){
    if(S[Root2] < S[Root1]){
        S[Root2] += S[Root1];
        S[Root1] = Root2;
    }
    else{
       //if(S[Root1] == S[Roo2]) S[Root1]++;
        S[Root1] += S[Root2];
        S[Root2] = Root1;
    }

}

void Initialization(SetType S, int n){
    for(int i=0; i<n; ++i){
        S[i] = -1;
    }
}

void Input_connection(SetType S){
    ElementType u, v;
    SetName Root1, Root2;
    scanf("%d %d\n", &u, &v);
    Root1 = Find(S, u-1);
    Root2 = Find(S, v-1);
    if(Root1 != Root2)
        Union( S, Root1, Root2);
}

void Check_connection(SetType S){
    ElementType u, v;
    SetName Root1, Root2;
    scanf("%d %d\n", &u, &v);
    Root1 = Find(S, u-1);
    Root2 = Find(S, v-1);
    if(Root1 == Root2){
        printf("yes\n");
    }
    else printf("no\n");
}

void Check_network(SetType S, int n){
    int counter = 0;
    for(int i = 0; i < n; i++){
        if(S[i] < 0){
            counter++;
        }
    }
    if(counter == 1){
        printf("The network is connected.\n");
    }
    else{
        printf("There are %d components.\n", counter);
    }
}

int main()
{
    SetType S;
    int n;
    char in;
    scanf("%d", &n);
    Initialization(S, n);
    do {
        scanf("%c", &in);
        switch(in){
            case 'I': Input_connection(S); break;
            case 'C': Check_connection(S); break;
            case 'S': Check_network(S, n); break;
        }
    }while(in != 'S');
    return 0;
}

測試結果：