数据结构C语言：图的深度广度遍历

深度遍历

图的深度遍历是一个递归的过程，类似于树的先序遍历。
遍历过程：从某个顶点v出发，首先访问该顶点，然后依次从它的各个未被访问的点，直至图中所有和v有路径相通的顶点都被访问到。 若此时尚有其他顶点未被访问到，则另选一个未被访问的顶点作起始点，重复上述过程，直至图中所有顶点都被访问到为止。

//深度遍历（用递归） 
void depthFirstTranverse(GraphPtr paraGraphPtr, int paraNode) {
	int i;
	
	visitedPtr[paraNode] = 1;
	printf("%d\t", paraNode);
	
	for (i = 0; i < paraGraphPtr -> numNodes; i ++) {
		if (!visitedPtr[i]){ 
			if (paraGraphPtr -> connections[paraNode][i]) {
				depthFirstTranverse(paraGraphPtr, i);
			}
		}
	}
}

广度遍历

广度优先遍历用队列实现

//广度遍历（队列实现） 
void widthFirstTranverse(GraphPtr paraGraphPtr, int paraStart){
	int i, j, tempNode;
	i = 0;
	QueuePtr tempQueuePtr = initQueue();
	printf("%d\t", paraStart);
	visitedPtr[paraStart] = 1;
	enqueue(tempQueuePtr, paraStart);
	while (!isQueueEmpty(tempQueuePtr)) {
		tempNode = dequeue(tempQueuePtr);
		visitedPtr[tempNode] = 1;
		
		i ++;

		for (j = 0; j < paraGraphPtr->numNodes; j ++) {
			if (visitedPtr[j]) 
				continue;

			if (paraGraphPtr->connections[tempNode][j] == 0)
				continue;
			
			printf("%d\t", j);
			visitedPtr[j] = 1;
			enqueue(tempQueuePtr, j);
		}
	}
}

完整代码

#include 
#include 

#define QUEUE_SIZE 10

int* visitedPtr;

//创建链队列 
typedef struct GraphNodeQueue{
	int* nodes;
	int front;
	int rear;
}GraphNodeQueue, *QueuePtr;

//初始化 
QueuePtr initQueue(){
	QueuePtr resultQueuePtr = (QueuePtr)malloc(sizeof(struct GraphNodeQueue));
	resultQueuePtr->nodes = (int*)malloc(QUEUE_SIZE * sizeof(int));
	resultQueuePtr->front = 0;
	resultQueuePtr->rear = 1;
	return resultQueuePtr;
}

//判断队列是否为空 
bool isQueueEmpty(QueuePtr paraQueuePtr){
	if ((paraQueuePtr->front + 1) % QUEUE_SIZE == paraQueuePtr->rear) {
		return true;
	}

	return false;
}

//入队 
void enqueue(QueuePtr paraQueuePtr, int paraNode){
	if ((paraQueuePtr->rear + 1) % QUEUE_SIZE == paraQueuePtr->front % QUEUE_SIZE) {
		printf("Error, trying to enqueue %d. queue full.\r\n", paraNode);
		return;
	}
	paraQueuePtr->nodes[paraQueuePtr->rear] = paraNode;
	paraQueuePtr->rear = (paraQueuePtr->rear + 1) % QUEUE_SIZE;
}

//出队 
int dequeue(QueuePtr paraQueuePtr){
	if (isQueueEmpty(paraQueuePtr)) {
		printf("Error, empty queue\r\n");
		return NULL;
	}

	paraQueuePtr->front = (paraQueuePtr->front + 1) % QUEUE_SIZE;

	return paraQueuePtr->nodes[paraQueuePtr->front];
}

//创建图 
typedef struct Graph{
	int** connections;
	int numNodes;
} *GraphPtr;

//图的初始化 
GraphPtr initGraph(int paraSize, int** paraData) {
	int i, j;
	GraphPtr resultPtr = (GraphPtr)malloc(sizeof(Graph));
	resultPtr -> numNodes = paraSize;
	resultPtr -> connections = (int**)malloc(paraSize * sizeof(int*));
	
	for (i = 0; i < paraSize; i ++) {
		resultPtr -> connections[i] = (int*)malloc(paraSize * sizeof(int));
		for (j = 0; j < paraSize; j ++) {
			resultPtr -> connections[i][j] = paraData[i][j];
		}
	}
	
	return resultPtr;
}

//遍历数组的初始化 
void initTranverse(GraphPtr paraGraphPtr) {
	int i;
	visitedPtr = (int*) malloc(paraGraphPtr -> numNodes * sizeof(int));
	
	for (i = 0; i < paraGraphPtr -> numNodes; i ++) {
		visitedPtr[i] = 0;
	}
}

//深度遍历（用递归） 
void depthFirstTranverse(GraphPtr paraGraphPtr, int paraNode) {
	int i;
	
	visitedPtr[paraNode] = 1;
	printf("%d\t", paraNode);
	
	for (i = 0; i < paraGraphPtr -> numNodes; i ++) {
		if (!visitedPtr[i]){ 
			if (paraGraphPtr -> connections[paraNode][i]) {
				depthFirstTranverse(paraGraphPtr, i);
			}
		}
	}
}

//广度遍历（队列实现） 
void widthFirstTranverse(GraphPtr paraGraphPtr, int paraStart){
	int i, j, tempNode;
	i = 0;
	QueuePtr tempQueuePtr = initQueue();
	printf("%d\t", paraStart);
	visitedPtr[paraStart] = 1;
	enqueue(tempQueuePtr, paraStart);
	while (!isQueueEmpty(tempQueuePtr)) {
		tempNode = dequeue(tempQueuePtr);
		visitedPtr[tempNode] = 1;
		
		i ++;

		for (j = 0; j < paraGraphPtr->numNodes; j ++) {
			if (visitedPtr[j]) 
				continue;

			if (paraGraphPtr->connections[tempNode][j] == 0)
				continue;
			
			printf("%d\t", j);
			visitedPtr[j] = 1;
			enqueue(tempQueuePtr, j);
		}
	}
}

//测试 
void testGraphTranverse() {
	int i, j;
	int myGraph[5][5] = { 
		{0, 1, 0, 1, 0},
		{1, 0, 1, 0, 1}, 
		{0, 1, 0, 1, 1}, 
		{1, 0, 1, 0, 0}, 
		{0, 1, 1, 0, 0}};
	int** tempPtr;
	printf("Preparing data\r\n");
		
	tempPtr = (int**)malloc(5 * sizeof(int*));
	for (i = 0; i < 5; i ++) {
		tempPtr[i] = (int*)malloc(5 * sizeof(int));
	}
	 
	for (i = 0; i < 5; i ++) {
		for (j = 0; j < 5; j ++) {
			tempPtr[i][j] = myGraph[i][j];
		}
	}
 
	printf("Data ready\r\n");
	
	GraphPtr tempGraphPtr = initGraph(5, tempPtr);
	printf("num nodes = %d \r\n", tempGraphPtr -> numNodes);
	printf("Graph initialized\r\n");

	printf("Depth first visit:\r\n");
	initTranverse(tempGraphPtr);
	depthFirstTranverse(tempGraphPtr, 4);

	printf("\r\nWidth first visit:\r\n");
	initTranverse(tempGraphPtr);
	widthFirstTranverse(tempGraphPtr, 4);
}

int main(){
	testGraphTranverse();
}

运行结果

Preparing data
Data ready
num nodes = 5
Graph initialized
Depth first visit:
4       1       0       3       2
Width first visit:
4       1       2       0       3
--------------------------------
Process exited after 0.02817 seconds with return value 0
请按任意键继续. . .