C++笔记-二维棋盘数组使用BFS（宽度优先遍历）
Posted IT1995
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这里只对一个顶点只能上下左右，不能和左上，左下，右上，右下连起来。
思路步骤：
1.二维棋盘数据转链接表；
2.邻接表直接进行BFS
源码如下：
#include <QDebug>
#include <QVector>
#include <QQueue>
#define MAX_COLUMN 6 + 2
#define MAX_ROW 6 + 2
//用-1包住，保证处理的统一
int map1[MAX_ROW][MAX_COLUMN] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, 1, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, 1, 1, 0, -1,
-1, -1, -1, -1, -1, -1, -1, -1
};
struct Point{
Point(int vNum, int x, int y) {
this->vNum = vNum;
this->x = x;
this->y = y;
}
int vNum = -1; //顶点号
int x; //x轴
int y; //y轴
friend QDebug operator << (QDebug os, Point &test){
os << "(顶点:" << test.vNum << ", x:" << test.x << ", y:" << test.y << ")";
return os;
}
};
class Graph {
public:
Graph(int map[MAX_ROW][MAX_COLUMN]) {
memcpy(m_map, map, sizeof(m_map));
//不为-1的都是顶点
int vCount = 0;
for (int i = 0; i < MAX_ROW; i++) {
for (int j = 0; j < MAX_COLUMN; j++) {
if (map[i][j] != -1) {
Point point(vCount++, i, j);
QVector<Point> ve;
ve.append(point);
m_adj.append(ve);
}
}
}
if (vCount == 0) {
qDebug() << "退出" << endl;
exit(-1);
}
this->m_v = vCount;
analysisEdge();
}
//打印邻接表
void print() {
for (int i = 0; i < this->m_v; ++i) {
qDebug() << "顶点:" << this->m_adj[i][0].vNum << " x:" << this->m_adj[i][0].x << " y:" << this->m_adj[i][0].y << " 的邻接表!";
for (int j = 0; j < this->m_adj[i].size(); j++) {
qDebug() << "顶点:" << this->m_adj[i][j].vNum << " x:" << this->m_adj[i][j].x << " y:" << this->m_adj[i][j].y;
}
qDebug() << "------------------------------------";
}
}
void bfs(int startV){
bool visited[this->m_v];
for(int i = 0; i < this->m_v; i++){
visited[i] = false;
}
Point point = getPointByVertex(startV);
if(point.vNum == -1){
qDebug() << "顶点错误!";
exit(0);
}
QQueue<Point> queue;
queue.push_back(point);
visited[startV] = true;
while(!queue.empty()){
Point s = queue.front();
queue.pop_front();
// start todo something
qDebug() << s;
// end todo something
for(int i = 0; i < this->m_adj[s.vNum].size(); i++){
int curretV = this->m_adj[s.vNum][i].vNum;
if(visited[curretV] == false){
visited[curretV] = true;
queue.push_back(this->m_adj[s.vNum][i]);
}
}
}
}
protected:
//通过坐标获取顶点号
Point getPointByPosXAndPosY(int x, int y) {
for (int i = 0; i < this->m_v; i++) {
if (this->m_adj[i][0].x == x && this->m_adj[i][0].y == y) {
return this->m_adj[i][0];
}
}
return Point(-1, -1, -1);
}
//通过顶点号返回Point
Point getPointByVertex(int v){
for(int i = 0; i < this->m_v; i++){
if(this->m_adj[i][0].vNum == v){
return this->m_adj[i][0];
}
}
return Point(-1, -1, -1);
}
void analysisEdge() {
//分析下边，这个顶点，如果周围一圈都是非-1的数，说明都可达。
for (int i = 0; i < this->m_v; i++) {
//左上
// if (m_map[this->m_adj[i][0].x - 1][this->m_adj[i][0].y - 1] != -1) {
// Point point = getPointByPosXAndPosY(this->m_adj[i][0].x - 1, this->m_adj[i][0].y - 1);
// if (point.vNum != -1) {
// //顶点是从1开始算，但下标是从0开始
// m_adj[this->m_adj[i][0].vNum].push_back(point);
// }
// }
//正上
if (m_map[this->m_adj[i][0].x - 1][this->m_adj[i][0].y] != -1) {
Point point = getPointByPosXAndPosY(this->m_adj[i][0].x - 1, this->m_adj[i][0].y);
if (point.vNum != -1) {
//顶点是从1开始算，但下标是从0开始
m_adj[this->m_adj[i][0].vNum].push_back(point);
}
}
//右上
// if (m_map[this->m_adj[i][0].x - 1][this->m_adj[i][0].y + 1] != -1) {
// Point point = getPointByPosXAndPosY(this->m_adj[i][0].x - 1, this->m_adj[i][0].y + 1);
// if (point.vNum != -1) {
// //顶点是从1开始算，但下标是从0开始
// m_adj[this->m_adj[i][0].vNum].push_back(point);
// }
// }
//正右
if (m_map[this->m_adj[i][0].x][this->m_adj[i][0].y + 1] != -1) {
Point point = getPointByPosXAndPosY(this->m_adj[i][0].x, this->m_adj[i][0].y + 1);
if (point.vNum != -1) {
//顶点是从1开始算，但下标是从0开始
m_adj[this->m_adj[i][0].vNum].push_back(point);
}
}
//右下
// if (m_map[this->m_adj[i][0].x + 1][this->m_adj[i][0].y + 1] != -1) {
// Point point = getPointByPosXAndPosY(this->m_adj[i][0].x + 1, this->m_adj[i][0].y + 1);
// if (point.vNum != -1) {
// //顶点是从1开始算，但下标是从0开始
// m_adj[this->m_adj[i][0].vNum].push_back(point);
// }
// }
//正下
if (m_map[this->m_adj[i][0].x + 1][this->m_adj[i][0].y] != -1) {
Point point = getPointByPosXAndPosY(this->m_adj[i][0].x + 1, this->m_adj[i][0].y);
if (point.vNum != -1) {
//顶点是从1开始算，但下标是从0开始
m_adj[this->m_adj[i][0].vNum].push_back(point);
}
}
//左下
// if (m_map[this->m_adj[i][0].x + 1][this->m_adj[i][0].y - 1] != -1) {
// Point point = getPointByPosXAndPosY(this->m_adj[i][0].x + 1, this->m_adj[i][0].y - 1);
// if (point.vNum != -1) {
// //顶点是从1开始算，但下标是从0开始
// m_adj[this->m_adj[i][0].vNum].push_back(point);
// }
// }
//正左
if (m_map[this->m_adj[i][0].x][this->m_adj[i][0].y - 1] != -1) {
Point point = getPointByPosXAndPosY(this->m_adj[i][0].x, this->m_adj[i][0].y - 1);
if (point.vNum != -1) {
//顶点是从1开始算，但下标是从0开始
m_adj[this->m_adj[i][0].vNum].push_back(point);
}
}
}
}
private:
int m_v; //顶点的个数
int m_map[MAX_ROW][MAX_COLUMN];
QVector<QVector<Point>> m_adj;
};
int main(int argc, char *argv[]) {
Q_UNUSED(argc)
Q_UNUSED(argv)
Graph g(map1);
g.print();
g.bfs(0);
getchar();
return 0;
}如下二维棋盘：
int map1[MAX_ROW][MAX_COLUMN] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, 1, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, -1, -1, 0, -1,
-1, -1, -1, -1, 1, 1, 0, -1,
-1, -1, -1, -1, -1, -1, -1, -1
};BFS是这样的（从第1个顶点（下标为0）开始）：
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