背景
多年前曾经写过C语言求解华容道,当时没有用到哈希表,导致整个查重搜索数组过大,每次求解都得花上数分钟的时间,如今时过境迁,对数据结构和算法有了更深的理解,所以得把这一块补上了。(其实就是最近想换工作,发现都喜欢算法大佬,所以写一个来敲一敲面试官的脑壳)
游戏
华容道挑战 7724游戏
方案
把曹操格子用1表示,横将用2表示,竖将用3表示,小兵用4表示,空地用0表示,上图可以转化了代号
2244
3110
3110
3433
3433
把上术内容保存到文本文件problem.txt当中
编写源文件main.c,内容为
/*==============依赖库导入 start================*/
#include<stdio.h> /* 标准输入输出库 */
#include<string.h> /* 字符串处理库 */
#include<malloc.h> /* 动态内存管理库 */
/*==============依赖库导入 end==================*//*================宏定义 start==================*/
/* 格子宏 */
#define SPACE '0' /* 空格 */
#define BIG '1' /* 大格 */
#define HORIZONTAL '2' /* 横格 */
#define VERTICAL '3' /* 竖格 */
#define SMALL '4' /* 小格 */
/* 方向宏 */
#define UP 1 /* 上 */
#define DOWN 2 /* 下 */
#define LEFT 3 /* 左 */
#define RIGHT 4 /* 右 */
/* 哈希宏 */
#define PRIMER 31 /* 素数系数 */
#define MOD 10007 /* 素数哈希 */
/*================宏定义 end====================*//*===============数据结构 start=================*/
typedef struct LinkList { /* 链表 */char *str; /* 字符串 */struct LinkList *next; /* 下一个节点指针 */
} LinkList;typedef struct HashSet { /* 哈希集合 */LinkList *linkList[MOD]; /* 链表数组 */
} HashSet;typedef struct Block { /* 方块 */char type; /* 类型 */int x; /* 左上角横坐标 */int y; /* 左上角纵坐标 */int w,h; /* 格子宽高 */struct Block *next; /* 下一个节点 */
} Block;typedef struct Operation { /* 操作 */int x,y; /* 格子位置 */int direction; /* 移动类型 */
} Operation;typedef struct Node { /* 节点 */char **arr; /* 字符数组 */Operation *operation; /* 上一步操作 */struct Node *previous; /* 上一个节点 */struct Node *next; /* 下一个节点 */
} Node;typedef struct Queue { /* 队列 */Node *head; /* 队头 */Node *tail; /* 队尾 */int count; /* 数量 */
} Queue;
/*===============数据结构 end===================*//* 从文件读取题目 */
void readProblemFile(char **arr,char *filepath) {freopen(filepath,"r",stdin);int i,j;for(i=0; i<5; i++) {scanf("%s",arr[i]);printf("%s\n",arr[i]);}printf("\n");
}/* 获取字符数组哈希码 */
int hashCode(char **arr,char value[]) {int res=0;int i,j,k=0;for(i=0; i<5; i++) {for(j=0; j<4; j++) {value[k]=arr[i][j];k++;res=res*PRIMER+arr[i][j]-'0';res%=MOD;}}return res;
}/* 往哈希表中添加对象 */
int addObjectToHashSet(char **arr,HashSet *hashSet) {char value[21]= {'\0'};int code=hashCode(arr,value);LinkList *linkList=hashSet->linkList[code];while(linkList!=NULL) {if(strcmp(linkList->str,value)==0) {return 0;} else {linkList=linkList->next;}}LinkList *listHead=(LinkList*)malloc(sizeof(LinkList));listHead->str=(char*)malloc(sizeof(char)*21);strcpy(listHead->str,value);listHead->next=hashSet->linkList[code];hashSet->linkList[code]=listHead;return 1;
}/* 释放哈希表 */
void freeHashSet(HashSet *hashSet) {int i;for(i=0; i<MOD; i++) {while(hashSet->linkList[i]!=NULL) {LinkList *linkList=hashSet->linkList[i];hashSet->linkList[i]=hashSet->linkList[i]->next;free(linkList);}}free(hashSet);
}/* 入队 */
void enQueue(char **arr,int x,int y,int direction,Queue *queue) {int i;Node *node=(Node*)malloc(sizeof(Node));node->arr=(char**)malloc(sizeof(char*)*5);for(i=0; i<5; i++) {node->arr[i]=(char*)malloc(sizeof(char)*5);strcpy(node->arr[i],arr[i]);}if(x==-1||y==-1||direction==-1) {node->operation=NULL;} else {node->operation=(Operation*)malloc(sizeof(Operation));node->operation->x=x;node->operation->y=y;node->operation->direction=direction;}node->previous=NULL;node->next=NULL;if(queue->head==NULL) {queue->head=node;queue->tail=node;queue->count=0;} else {queue->tail->next=node;node->previous=queue->head;queue->tail=node;}queue->count++;
}/* 出队 */
void deQueue(Queue *queue) {queue->head=queue->head->next;queue->count--;
}/* 释放队列 */
void freeQueue(Queue *queue) {while(queue->head!=NULL) {Node* node=queue->head;queue->head=queue->head->next;if(node->operation!=NULL) {free(node->operation);}if(node->arr!=NULL) {int i;for(i=0; i<5; i++) {free(node->arr[i]);}free(node->arr);}}free(queue);
}/* 生成格子链表 */
Block* getBlocks(char **arr) {int i,j,u,v;Block* blocks=NULL;char temp[5][4]= {0};for(i=0; i<5; i++) {strcpy(temp[i],arr[i]);}for(i=0; i<5; i++) {for(j=0; j<4; j++) {if(temp[i][j]==SPACE) {continue;}Block *block=(Block*)malloc(sizeof(Block));block->next=blocks;blocks=block;block->type=temp[i][j];block->x=i;block->y=j;switch(temp[i][j]) {case BIG:block->w=2;block->h=2;break;case HORIZONTAL:block->w=2;block->h=1;break;case VERTICAL:block->w=1;block->h=2;break;case SMALL:block->w=1;block->h=1;break;}for(u=i; u<i+block->h; u++) {for(v=j; v<j+block->w; v++) {temp[u][v]=SPACE;}}}}return blocks;
}/* 释放格子链表 */
void freeBlocks(Block *blocks) {while(blocks->next!=NULL) {Block *block=blocks;blocks=blocks->next;free(block);}
}/* 创建字符数组 */
char** createArray() {int i,j;char** res=(char**)malloc(sizeof(char*)*5);for(i=0; i<5; i++) {res[i]=(char*)malloc(sizeof(char)*5);for(j=0; j<4; j++) {res[i][j]='0';}res[i][4]='\0';}return res;
}/* 释放字符数组 */
void freeArray(char **arr) {int i;for(i=0; i<5; i++) {free(arr[i]);}free(arr);
}/* 方块转字符数组 */
void blocksToArray(Block *blocks,char **arr) {int i,j;while(blocks!=NULL) {Block *block=blocks;blocks=blocks->next;for(i=block->x; i<block->x+block->h; i++) {for(j=block->y; j<block->y+block->w; j++) {arr[i][j]=block->type;}}}
}/* 打印所求结果 */
void displaySolution(Node *node) {if(node->operation==NULL) {return;} else {displaySolution(node->previous);int i;char directionName[][10]= {"","↑","↓","←","→"};printf("[%d,%d] %s\n",node->operation->x,node->operation->y,directionName[node->operation->direction]);}
}/* 主函数 */
int main(int argc,char *argv[]) {char **array=(char**)malloc(sizeof(char*)*5);int i,j;for(i=0; i<5; i++) {array[i]=(char*)malloc(sizeof(char)*5);array[i][4]='\0';}if(argc==2) {readProblemFile(array,argv[1]);} else {strcpy(array[0],"3113\0");strcpy(array[1],"3113\0");strcpy(array[2],"3223\0");strcpy(array[3],"3443\0");strcpy(array[4],"4004\0");}HashSet hashSet;for(i=0; i<MOD; i++) {hashSet.linkList[i]=NULL;}Queue queue;queue.head=NULL;queue.tail=NULL;Node *result=NULL;addObjectToHashSet(array,&hashSet);enQueue(array,-1,-1,-1,&queue);free(array);while(queue.head!=NULL) {Node *node=queue.head;if(node->arr[3][1]==BIG && node->arr[4][2]==BIG) {result=node;break;}Block *blocks=getBlocks(node->arr);Block *blocksHead=blocks;while(blocksHead!=NULL) {Block *block=blocksHead;blocksHead=blocksHead->next;char **arr=NULL;switch(block->type) {case BIG:if(block->x>0 && node->arr[block->x-1][block->y]==SPACE && node->arr[block->x-1][block->y+1]==SPACE) {arr=createArray();block->x--;blocksToArray(blocks,arr);block->x++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,UP,&queue);}}if(block->x+block->h<5 && node->arr[block->x+block->h][block->y]==SPACE && node->arr[block->x+block->h][block->y+1]==SPACE) {arr=createArray();block->x++;blocksToArray(blocks,arr);block->x--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,DOWN,&queue);}}if(block->y>0 && node->arr[block->x][block->y-1]==SPACE && node->arr[block->x+1][block->y-1]==SPACE) {arr=createArray();block->y--;blocksToArray(blocks,arr);block->y++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,LEFT,&queue);}}if(block->y+block->w<4 && node->arr[block->x][block->y+block->w]==SPACE && node->arr[block->x+1][block->y+block->w]==SPACE) {arr=createArray();block->y++;blocksToArray(blocks,arr);block->y--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,RIGHT,&queue);}}break;case HORIZONTAL:if(block->x>0 && node->arr[block->x-1][block->y]==SPACE && node->arr[block->x-1][block->y+1]==SPACE) {arr=createArray();block->x--;blocksToArray(blocks,arr);block->x++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,UP,&queue);}}if(block->x+block->h<5 && node->arr[block->x+block->h][block->y]==SPACE && node->arr[block->x+block->h][block->y+1]==SPACE) {arr=createArray();block->x++;blocksToArray(blocks,arr);block->x--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,DOWN,&queue);}}if(block->y>0 && node->arr[block->x][block->y-1]==SPACE) {arr=createArray();block->y--;blocksToArray(blocks,arr);block->y++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,LEFT,&queue);}}if(block->y+block->w<4 && node->arr[block->x][block->y+block->w]==SPACE) {arr=createArray();block->y++;blocksToArray(blocks,arr);block->y--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,RIGHT,&queue);}}break;case VERTICAL:if(block->x>0 && node->arr[block->x-1][block->y]==SPACE) {arr=createArray();block->x--;blocksToArray(blocks,arr);block->x++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,UP,&queue);}}if(block->x+block->h<5 && node->arr[block->x+block->h][block->y]==SPACE) {arr=createArray();block->x++;blocksToArray(blocks,arr);block->x--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,DOWN,&queue);}}if(block->y>0 && node->arr[block->x][block->y-1]==SPACE && node->arr[block->x+1][block->y-1]==SPACE) {arr=createArray();block->y--;blocksToArray(blocks,arr);block->y++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,LEFT,&queue);}}if(block->y+block->w<4 && node->arr[block->x][block->y+block->w]==SPACE && node->arr[block->x+1][block->y+block->w]==SPACE) {arr=createArray();block->y++;blocksToArray(blocks,arr);block->y--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,RIGHT,&queue);}}break;case SMALL:if(block->x>0 && node->arr[block->x-1][block->y]==SPACE) {arr=createArray();block->x--;blocksToArray(blocks,arr);block->x++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,UP,&queue);}}if(block->x+block->h<5 && node->arr[block->x+block->h][block->y]==SPACE) {arr=createArray();block->x++;blocksToArray(blocks,arr);block->x--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,DOWN,&queue);}}if(block->y>0 && node->arr[block->x][block->y-1]==SPACE) {arr=createArray();block->y--;blocksToArray(blocks,arr);block->y++;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,LEFT,&queue);}}if(block->y+block->w<4 && node->arr[block->x][block->y+block->w]==SPACE) {arr=createArray();block->y++;blocksToArray(blocks,arr);block->y--;if(addObjectToHashSet(arr,&hashSet)) {enQueue(arr,block->x,block->y,RIGHT,&queue);}}break;}}while(blocks!=NULL) {blocksHead=blocks;blocks=blocks->next;free(blocksHead);}deQueue(&queue);}if(result!=NULL) {printf("求解完成\n");displaySolution(result);} else {printf("此题无解\n");}freeHashSet(&hashSet);freeQueue(&queue); return 0;
}
编译源文件main.c得到可执行程序main.exe,把main.exe和problem.txt放在同一个文件夹下。
使用cmd打开此目录,执行命令
main.exe problem.txt > 1.txt
稍后便可在目录下生成1.txt文件,里边保存的就是游戏的通关参考答案。
2244
3110
3110
3433
3433求解完成
[3,3] ↑
[2,3] ↑
[3,2] →
[4,1] →
[3,1] ↓
[1,1] ↓
[0,2] ↓
[1,2] ←
[0,3] ←
[1,3] ↑
[3,3] ↑
[4,2] →
[0,2] ↓
[0,0] →
[1,0] ↑
[3,0] ↑
[4,1] ←
[2,1] ↓
思路
之前已经有博文进行了详细介绍,此处不再赘述。