数据结构实验之图论二：基于邻接表的广度优先搜索遍历
Time Limit: 1000 ms Memory Limit: 65536 KiB
Problem Description
给定一个无向连通图，顶点编号从0到n-1，用广度优先搜索(BFS)遍历，输出从某个顶点出发的遍历序列。(同一个结点的同层邻接点，节点编号小的优先遍历）
Input
输入第一行为整数n（0< n <100），表示数据的组数。
对于每组数据，第一行是三个整数k，m，t（0＜k＜100，0＜m＜(k-1)*k/2，0＜ t＜k），表示有m条边，k个顶点，t为遍历的起始顶点。
下面的m行，每行是空格隔开的两个整数u，v，表示一条连接u，v顶点的无向边。
Output
输出有n行，对应n组输出，每行为用空格隔开的k个整数，对应一组数据，表示BFS的遍历结果。
Sample Input
1 6 7 0 0 3 0 4 1 4 1 5 2 3 2 4 3 5
Sample Output
0 3 4 2 5 1
Hint
用邻接表存储。
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct node
{
int data;
struct node *next;
}*a[1001], *p, *q;
int flag[10001], stack[10001];
struct node *num[101]; //为什么num它总是自己会清NULL，明明是全局变量）
void build(int u, int v)
{
// struct node *x;
p = (struct node *)malloc(sizeof(struct node));
p-> data = v;
if(num[u] == NULL)
{
p-> next = NULL;
num[u] = p;
}
else
{
p-> next = num[u]-> next;
num[u]-> next = p;
}
q = (struct node *)malloc(sizeof(struct node));
q-> data = u;
if(num[v] == NULL)
{
q-> next = NULL;
num[v] = q;
}
else
{
q-> next = num[v]-> next;
num[v]-> next = q;
}
}
int search(struct node *head, int i)
{
while(head)
{
if(head -> data == i)
return 1;
else
head = head -> next;
}
return 0;
}
int main(void)
{
int n, i, k, m, t, u, v;
scanf("%d", &n);
while(n--)
{
scanf("%d %d %d", &k, &m, &t);
memset(flag, 0, sizeof(flag));
memset(stack, 0, sizeof(stack));
for(i = 0; i < m; i++)
{
scanf("%d %d", &u, &v);
build(u, v);
}
int l = 0, r = 0;
flag[t] = 1;
stack[r++] = t;
while(l < r)
{
for(i = 0; i < k; i++)
{
if(search(num[stack[l]], i) && flag[i] == 0)
{
stack[r++] = i;
flag[i] = 1;
}
}
printf("%d%c", stack[l], l == k - 1?'\n':' ');
l++;
}
}
return 0;
}
/*
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct node
{
int data;
struct node *next;
}*a[1001], *p, *q;
int flag[10001], stack[10001];
void build(struct node *num[], int u, int v)
{
// struct node *x;
p = (struct node *)malloc(sizeof(struct node));
p-> data = v;
if(num[u] == NULL)
{
p-> next = NULL;
num[u] = p;
}
else
{
p-> next = num[u]-> next;
num[u]-> next = p;
}
q = (struct node *)malloc(sizeof(struct node));
q-> data = u;
if(num[v] == NULL)
{
q-> next = NULL;
num[v] = q;
}
else
{
q-> next = num[v]-> next;
num[v]-> next = q;
}
}
int search(struct node *head, int i)
{
while(head)
{
if(head -> data == i)
return 1;
else
head = head -> next;
}
return 0;
}
int main(void)
{
int n, i, k, m, t, u, v;
scanf("%d", &n);
while(n--)
{
scanf("%d %d %d", &k, &m, &t);
struct node *num[101] = {NULL};;
memset(flag, 0, sizeof(flag));
memset(stack, 0, sizeof(stack));
for(i = 0; i < m; i++)
{
scanf("%d %d", &u, &v);
build(num, u, v);
}
int l = 0, r = 0;
flag[t] = 1;
stack[r++] = t;
while(l < r)
{
for(i = 0; i < k; i++)
{
if(search(num[stack[l]], i) && flag[i] == 0)
{
stack[r++] = i;
flag[i] = 1;
}
}
printf("%d%c", stack[l], l == k - 1?'\n':' ');
l++;
}
}
return 0;
}
/*
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int stack[110], flag[110];
struct node
{
int data;
struct node *next;
};
struct node *num[110];
void creat_list(int u, int v)
{
struct node *p, *q;
p = (struct node *)malloc(sizeof(struct node));
p -> data = v;
if(num[u] == NULL)
{
p -> next = NULL;
num[u] = p;
}
else
{
p -> next = num[u] -> next;
num[u] -> next = p;
}
q = (struct node *)malloc(sizeof(struct node));
q -> data = u;
if(num[v] == NULL)
{
q -> next = NULL;
num[v] = q;
}
else
{
q -> next = num[v] -> next;
num[v] -> next = q;
}
}
int search(struct node *head, int i)
{
while(head)
{
if(head -> data == i)
return 1;
else
head = head -> next;
}
return 0;
}
int main()
{
int t, n, m, k, u, v, i;
scanf("%d", &t);
while(t--)
{
memset(flag, 0, sizeof(flag));
memset(stack, 0, sizeof(stack));
scanf("%d%d%d", &n, &m, &k);
for(i = 0; i < m; i++)
{
scanf("%d%d", &u, &v);
creat_list(u, v);
}
int l = 0, r = 0;
flag[k] = 1;
stack[r++] = k;
while(l < r)
{
// printf("%d\n\n\n\n", n);
for(i = 0; i < n; i++)
{
if(search(num[stack[l]], i) && flag[i] == 0)
{
stack[r++] = i;
flag[i] = 1;
}
}
printf("%d%c", stack[l], l == n - 1 ? '\n' : ' ');
l++;
}
}
return 0;
}
*/
*/