全是套路——BFS

Posted 2020-08-04 EazyChange

#include <iostream>
#include <vector>
#include <string>
#include <vector>
#include <algorithm>
#include <stack>
#include <math.h>
#include <limits.h>
#include <set>
#include <memory>
#include <queue>

using namespace std;

struct point{
    int x;
    int y;
    point *parent;
    int step;
};

int map[9][9] = {         1, 1, 1, 1, 1, 1, 1, 1, 1,
                         1, 0, 0, 1, 0, 0, 1, 0, 1,
                         1, 0, 1, 1, 1, 0, 0, 0, 1,
                         1, 0, 1, 0, 0, 0, 0, 1, 1,
                         1, 0, 1, 0, 1, 1, 0, 0, 1,
                         1, 0, 1, 0, 1, 1, 0, 0, 1,
                         1, 0, 0, 0, 1, 1, 0, 0, 1,
                         1, 1, 0, 1, 1, 0, 0, 0, 1,
                         1, 1, 1, 1, 1, 1, 1, 1, 1, };


vector<point> p;
int BFS(point s,point e)
{
    queue<point> q;
    q.push(s);
    while (!q.empty())
    {
        point start = q.front();
        point *s1 = new point; s1->x = start.x; s1->y = start.y; s1->parent = start.parent;
        q.pop();
        if (start.x == e.x&&start.y == e.y)
        {
            p.push_back(start);
            return start.step;
        }
        if (map[start.x + 1][start.y] != 1 && start.x + 1 <= 8 && start.x + 1 >= 0)
        {
            point tmp = { start.x + 1, start.y, s1, start.step + 1 };
            map[start.x + 1][start.y] = 1;
            q.push(tmp);
        }
        if (map[start.x - 1][start.y] != 1 && start.x - 1 <= 8 && start.x - 1 >= 0)
        {
            point tmp = { start.x - 1, start.y, s1, start.step + 1 };
            map[start.x - 1][start.y] = 1;
            q.push(tmp);
        }
        if (map[start.x][start.y + 1] != 1 && start.y + 1 <= 8 && start.y + 1 >= 0)
        {
            point tmp = { start.x, start.y + 1, s1, start.step + 1 };
            map[start.x][start.y + 1] = 1;
            q.push(tmp);
        }
        if (map[start.x][start.y - 1] != 1 && start.y - 1 <= 8 && start.y - 1 >= 0)
        {
            point tmp = { start.x, start.y - 1, s1, start.step + 1 };
            map[start.x][start.y - 1] = 1;
            q.push(tmp);
        }
        start.step++;
    }

}

int main()
{
    point s = { 1, 1 }, e = { 7, 7 };
    BFS(s, e);
    char p1[15] = "abcd", *p2 = "ABCD", str[50] = "xyz";
    strcpy(str + 2, strcat(p1 + 2, p2 + 1));
    printf("%s", str);
    point *point = &p[0];
    while (point->parent != NULL)
    {
        cout << point->x << " " << point->y << endl;
        point = point->parent;
    }
    return 0;
}