[刷题] 走迷宫

用栈实现深度优先遍历

#include <iostream>
#define MAX_ROW 5
#define MAX_COL 5

struct point { int row, col; } stack[512];
int top = 0;

void push(struct point p)
{
    stack[top] = p;
    top++;
}

struct point pop(void)
{
    top--;
    return stack[top];
}

int is_empty(void)
{
    return top == 0;
}

int maze[MAX_ROW][MAX_COL] = {
    0,1,0,0,0,
    0,1,0,1,0,
    0,0,0,1,0,
    0,1,1,1,0,
    0,0,0,1,0,    
};

void print_maze(void)
{
    int i, j;
    for(i = 0; i < MAX_ROW; i++){
        for(j = 0; j < MAX_COL; j++)
            printf("%d",maze[i][j]);
        putchar('
');
    }
    printf("************
");
}

struct point predecessor[MAX_ROW][MAX_COL] = {
    {{-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}},
    {{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1}},
    {{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1}},    
};

void visit(int row, int col, struct point pre)
{
    struct point visit_point = { row, col};
    maze[row][col] = 2;
    predecessor[row][col] = pre;
    push(visit_point);
}

int main(void)
{
    struct point p = { 0, 0};
    
    maze[p.row][p.col] = 2;
    push(p);
    
    while (!is_empty()){
        p = pop();
        if (p.row == MAX_ROW - 1  /* goal */
            && p.col == MAX_COL - 1)
            break;
        if (p.col+1 < MAX_COL     /* right */
            && maze[p.row][p.col+1] == 0)
            visit(p.row, p.col+1, p);
        if (p.row+1 < MAX_ROW     /* down */
            && maze[p.row+1][p.col] == 0)
            visit(p.row+1, p.col, p);
        if (p.col-1 >= 0          /* left */
            && maze[p.row][p.col-1] == 0)
            visit(p.row, p.col-1, p);
        if (p.row-1 >= 0          /* up */
            && maze[p.row-1][p.col] == 0)
            visit(p.row-1, p.col, p);
        print_maze();
    }
    if (p.row == MAX_ROW -1 && p.col == MAX_COL -1) {
        printf("(%d,%d)
", p.row, p.col);
        while(predecessor[p.row][p.col].row != -1) {
            p = predecessor[p.row][p.col];
            printf("(%d, %d)
",p.row, p.col);
        }
    }else
        printf("No path!
");
    
    return 0;
}

结果：