將起點標記為已走過并壓棧;
while (棧非空) {
從棧頂彈出一個點p;
if (p這個點是終點)
break;
否則沿右、下、左、上四個方向探索相鄰的點
if (和p相鄰的點有路可走，并且還沒走過)
將相鄰的點標記為已走過并壓棧，它的前趨就是p點;
}
if (p點是終點) {
打印p點的坐標;
while (p點有前趨) {
p點 = p點的前趨;
打印p點的坐標;
}
} else
沒有路線可以到達終點;

#include <stdio.h>
#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;
}
struct point pop(void)
{
  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, 0, 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('\n');
  }
  printf("*********\n");
}
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)\n", p.row, p.col);
    while (predecessor[p.row][p.col].row != -1) {
      p = predecessor[p.row][p.col];
      printf("(%d, %d)\n", p.row,
      p.col);
    }
  } else
    printf("No path!\n");
    return 0;
}