leetcode490题，迷宫，求到某个点是否存在路径
leetcode505题，迷宫II，求到某个点的最小路径count
leetcode994题，腐烂的橘子，求各自中没有新鲜橘子经历的最小分钟数。
算法核心就是
1、写好入队函数的判断
2、写好外面函数入队的场景
3、二维数组需要构造结构体包含x，y坐标
迷宫我用maze[x][y]==2标识这个区域是否被访问过
迷宫II我用maze[x][y]来标识到达当前位置所花的时间
迷宫
#define MAXLEN 10000
typedef struct {
int x;
int y;
}Queue;
Queue g_queue[MAXLEN];
int Enqueue(int x, int y, int tail, int **maze)
{
if (maze[x][y] == 2) {
return tail;
}
else {
g_queue[tail].x = x;
g_queue[tail].y = y;
maze[x][y] = 2;
}
return tail + 1;
}
bool hasPath(int** maze, int mazeSize, int* mazeColSize, int* start, int startSize, int* destination, int destinationSize) {
int row, col, head, tail, dx, dy;
if (mazeSize == 0) {
return false;
}
if (start[0] == destination[0] && start[1] == destination[1]) {
return true;
}
row = mazeSize;
col = *mazeColSize;
dx = destination[0];
dy = destination[1];
head = 0;
tail = 0;
g_queue[tail].x = start[0];
g_queue[tail].y = start[1];
maze[g_queue[tail].x][g_queue[tail].y] = 2;
tail++;
int tmpx, tmpy, count;
while (head < tail) {
tmpx = g_queue[head].x;
tmpy = g_queue[head].y;
if (tmpx==dx && tmpy ==dy) {
return true;
}
while (tmpx - 1 >= 0 && maze[tmpx - 1][tmpy] != 1) {
tmpx--;
}
tail = Enqueue(tmpx, tmpy, tail,maze);
tmpx = g_queue[head].x;
while (tmpx + 1 < row && maze[tmpx + 1][tmpy] != 1) {
tmpx++;
}
tail = Enqueue(tmpx, tmpy, tail,maze);
tmpx = g_queue[head].x;
while (tmpy - 1 >= 0 && maze[tmpx][tmpy - 1] != 1) {
tmpy--;
}
tail = Enqueue(tmpx, tmpy, tail,maze);
tmpy = g_queue[head].y;
while (tmpy + 1 < col && maze[tmpx][tmpy + 1] != 1) {
tmpy++;
}
tail = Enqueue(tmpx, tmpy,tail,maze);
head++;
}
return false;
}
迷宫II
#define MAXLEN 10000
typedef struct {
int x;
int y;
}Queue;
Queue g_queue[MAXLEN];
int Enqueue(int x, int y, int count, int tail, int **maze)
{
//printf("x=%d y=%d count=%d premaze=%d \n", x, y, count, maze[x][y]);
if (maze[x][y] > 0 && maze[x][y] <= count) {
return tail;
}
else {
g_queue[tail].x = x;
g_queue[tail].y = y;
maze[x][y] = count;
}
//printf("x=%d y=%d count=%d premaze=%d \n", x, y, count, maze[x][y]);
return tail + 1;
}
int shortestDistance(int** maze, int mazeSize, int* mazeColSize, int* start, int startSize, int* destination, int destinationSize) {
int row, col, head, tail, dx, dy;
if (mazeSize == 0) {
return -1;
}
if (start[0] == destination[0] && start[1] == destination[1]) {
return 0;
}
row = mazeSize;
col = *mazeColSize;
dx = destination[0];
dy = destination[1];
head = 0;
tail = 0;
g_queue[tail].x = start[0];
g_queue[tail].y = start[1];
maze[g_queue[tail].x][g_queue[tail].y] = 2;
tail++;
int tmpx, tmpy, count;
while (head < tail) {
tmpx = g_queue[head].x;
tmpy = g_queue[head].y;
count = maze[tmpx][tmpy];
while (tmpx - 1 >= 0 && maze[tmpx - 1][tmpy] != 1) {
tmpx--;
count++;
}
tail = Enqueue(tmpx, tmpy, count, tail, maze);
tmpx = g_queue[head].x;
count = maze[tmpx][tmpy];
while (tmpx + 1 < row && maze[tmpx + 1][tmpy] != 1) {
tmpx++;
count++;
}
tail = Enqueue(tmpx, tmpy, count, tail, maze);
tmpx = g_queue[head].x;
count = maze[tmpx][tmpy];
while (tmpy - 1 >= 0 && maze[tmpx][tmpy - 1] != 1) {
tmpy--;
count++;
}
tail = Enqueue(tmpx, tmpy, count, tail, maze);
tmpy = g_queue[head].y;
count = maze[tmpx][tmpy];
while (tmpy + 1 < col && maze[tmpx][tmpy + 1] != 1) {
tmpy++;
count++;
}
tail = Enqueue(tmpx, tmpy, count, tail, maze);
head++;
}
if (maze[dx][dy] == 0) {
return -1;
}
return maze[dx][dy] - 2;
}
腐烂的橘子
#define MAXLEN 102
typedef struct{
int x;
int y;
}Queue;
Queue q[MAXLEN];
int Enqueue(int i, int j, int row, int col, int ** grid, int tail)
{
if (i < 0 || j < 0 || i >= row || j >= col) {
return tail;
}
if (grid[i][j] != 1) {
return tail;
}
grid[i][j] = 2;
q[tail].x = i;
q[tail].y = j;
return tail + 1;
}
int orangesRotting(int** grid, int gridSize, int* gridColSize) {
int i, j, tmpi, tmpj, row, col;
int head, tail;
head = 0;
tail = 0;
row = gridSize;
col = *gridColSize;
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
if (grid[i][j] == 2) {
q[tail].x = i;
q[tail].y = j;
tail++;
}
}
}
int number, min;
min = 0;
while (head < tail) {
number = tail - head;
for (i = 0; i < number; i++) {
tmpi = q[head].x;
tmpj = q[head].y;
head++;
tail = Enqueue(tmpi + 1, tmpj, row, col, grid, tail);
tail = Enqueue(tmpi - 1, tmpj, row, col, grid, tail);
tail = Enqueue(tmpi, tmpj + 1, row, col, grid, tail);
tail = Enqueue(tmpi, tmpj - 1, row, col, grid, tail);
}
if (head < tail){
min++;
}
}
for (i = 0; i < row; i++) {
for (j = 0; j < col; j++) {
if (grid[i][j] == 1) {
min = -1;
}
}
}
return min;
}