bfs

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <limits.h>
#include <malloc.h>
#include <stdlib.h>

int **maze;
int m, n;
int stepX[4] = { 1, 0, -1, 0 }, stepY[4] = { 0, 1, 0, -1 };

typedef struct point {
	int x, y;
}point;

typedef struct queue {
	point value;
	queue *next;
}queue;


void pushBack(queue **head, point data) {
	queue *p = (queue*)malloc(sizeof(queue)), *t;
	if (*head == NULL) {
		p->value = data;
		p->next = NULL;
		*head = p;
	}
	else {
		p->value = data;
		p->next = NULL;
		t = *head;
		while (t->next) t = t->next;
		t->next = p;
	}
}

point pop(queue **head) {
	queue *p = (queue*)(malloc(sizeof(queue)));
	point value;
	p = (*head);
	*head = (*head)->next;
	value = p->value;
	free(p);
	return(value);
}

int check(point p) {
	return(((0 <= p.x) && (p.x < n)) && ((0 <= p.y) && (p.y < m)) && maze[p.y][p.x] != -2);
}

int bfs(point s) {
	int i;
	point pCrt, pNext;
	queue *head = NULL;
	pushBack(&head, s);
	while (head) {
		pCrt = pop(&head);
		for (i = 0; i < 4; i++) {
			pNext.x = pCrt.x + stepX[i];
			pNext.y = pCrt.y + stepY[i];
			if (check(pNext) && (maze[pNext.y][pNext.x] == -1 || maze[pNext.y][pNext.x] == -4)) {
				if (maze[pNext.y][pNext.x] != -4) {
					maze[pNext.y][pNext.x] = maze[pCrt.y][pCrt.x] + 1;
					pushBack(&head, pNext);
				}
				else return(maze[pCrt.y][pCrt.x] + 1);
			}
		}
	}
	return -1;
} //обход в ширину

int main() {
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	int i, j;
	char c;
	point s;
	scanf("%d %d", &m, &n);
	maze = (int**)malloc(m * sizeof(int*));
	for (i = 0; i < m; i++) {
		maze[i] = (int*)malloc(n * sizeof(int));
		for (j = 0; j < n; j++) {
			scanf("%c", &c);
			if (c == '\n') scanf("%c", &c);
			if (c == '.') maze[i][j] = -1;
			if (c == 'X') maze[i][j] = -2;
			if (c == 'S') {
				maze[i][j] = 0;
				s.y = i;
				s.x = j;
			}
			if (c == 'F') maze[i][j] = -4;
		}
	}
	printf("%d", bfs(s));
}