贪食蛇游戏：代码分析和优化 - 避免食物缺失 - 常规

#include<stdio.h>\n#include<time.h>\n#include<windows.h>\n#include<stdlib.h>\n#include<conio.h>\n\n#define U 1\n#define D 2\n#define L 3\n#define R 4\n\n\n\typedef struct snake\n{\n int x; int y;\n struct snake *next;\n }snake;\n\n int score=0,add=10;\n int highscore=0;\n int status,sleeptime=200;\n snake *head,*food;\n snake q;\n int endgamestatus=0;\n HANDLE hOut;\n void gotoxy(int x,int y);\n int color(int c);\n void printsnake();\n void wlcome();\n void createmap();\n void scoreandtips();\n void initsnake();\n void createfood();\n int biteself();\n void cantcrosswall();\n void speedup();\n void speeddown();\n void snakemove();\n void keyboardcontrol();\n void lostdraw();\n void endgame();\n void choose();\n void file_out();\n void file_in();\n void explation();\n main()\n {\n system("mode con cols=100 lines=30");\n printsnake();\n wlcome();\n file_out();\n keyboardcontrol();\n endgame();\n }\n void gotoxy(int x,int y)//\n {COORD c;\n c.X=x;\n c.Y=y;\n SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE),c);\n }\n int color(int c)//\n {\n SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),c);\n return 0;\n }\n void printsnake()//\n {\n gotoxy(2,5);\n color(3);\n printf("姓名：张");\n \n gotoxy(2,6);\n color(3);\n printf("工号：1");\n }\n \n void wlcome()\n {int n;\n int i,j=1;\n gotoxy(43,18);\n color(11);\n printf("贪吃蛇");\n color(14);\n for(i=20;i<=26;i++)\n {\n for(j=27;j<=74;j++)\n {\n gotoxy(j,i);\n if(i==20||i==26)\n {\n printf("-");\n }\n else if(j==27||j==74)\n {\n printf("|");\n }\n }\n }\n color(12);\n gotoxy(35,22);\n printf("1.开始");\n gotoxy(55,22);\n printf("2.说明");\n gotoxy(35,24);\n printf("3.退出");\n gotoxy(29,27);\n color(3);\n printf("请选择1 2 3\n");\n color(14);\n scanf("%d",&n);\n switch(n)\n {\n case 1:\n system("cls");\n createmap();\n initsnake();\n createfood();\n keyboardcontrol();\n break;\n case 2:\n explation();\n break;\n break;\n case 3:\n exit(0);\n break;\n }\n }\nvoid createmap()\n{\n int i,j;\n for(i=0;i<58;i+=2)\n {\n gotoxy(i,0);\n color(5);\n printf("□");\n gotoxy(i,26);\n printf("□");\n }\n for(i=0;i<26;i++)\n {\n gotoxy(0,i);\n printf("□");\n gotoxy(56,i);\n printf("□");\n }\n for(i=2;i<56;i+=2)\n {\n for(j=1;j<26;j++)\n {\n gotoxy(i,j);\n color(3);\n printf("■\n\n");\n }\n \n }\n}\n void scoreandtips()//\n {\n file_out();\n gotoxy(64,4);\n color(11);\n printf("最高纪录: %d",highscore);\n gotoxy(64,8);\n color(14);\n printf("得分: %d ",score);\n color(13);\n gotoxy(73,11);\n printf("小提示");\n gotoxy(60,13);\n color(6);\n printf("+---------------------+");\n gotoxy(60,25);\n printf("+---------------------+");\n color(3);\n gotoxy(64,14);\n printf("每个食物得分：%d分",add);\n gotoxy(64,16);\n printf("不能、咬到自己");\n gotoxy(64,18);\n printf("↑↓←→控制蛇的移动");\n gotoxy(64,20);\n printf("F1加速，F2减速");\n gotoxy(64,22);\n printf("space: 暂停");\n gotoxy(64,24);\n printf("ESC:退出");\n}\nvoid file_out()\n{\n FILE fp;\n fp=fopen("save.txt","a+");\n fscanf(fp,"%d",&highscore);\n fclose(fp);\n }\n void initsnake()\n {\n snake tail;\n int i;\n tail=(snake)malloc(sizeof(snake));\n tail->x=24;\n tail->y=5;\n tail->next=NULL;\n for(i=1;i<=4;i++)\n {\n head=(snake)malloc(sizeof(snake));\n head->next=tail;\n head->x=24+2i;\n head->y=5;\n tail=head;\n }\n while(tail!=NULL)\n {gotoxy(tail->x,tail->y);\n color(14);\n printf("★");\n tail=tail->next;\n }\n}\nvoid createfood()\n{\n snake food_1;\n srand((unsigned)time(NULL));\n int flag = 0;\n while (!flag) {\n food_1 = (snake)malloc(sizeof(snake));\n food_1->x = rand() % 52 + 2;\n food_1->y = rand() % 24 + 1;\n q = head;\n flag = 1;\n while (q != NULL) {\n if (q->x == food_1->x && q->y == food_1->y) {\n flag = 0;\n break;\n }\n q = q->next;\n }\n if (flag) {\n gotoxy(food_1->x, food_1->y);\n food = food_1;\n color(12);\n printf("@");\n } else {\n free(food_1);\n }\n }\n}\nint biteself()\n{\n snake *self;\n self=head->next;\n while(self!=NULL)\n {\n if(self->x==head->x&&self->y==head->y)\n {\n return 1;\n }\n self=self->next;\n }\n return 0;\n }\n \n void cantcrosswall()\n{\n if(head->x==0||head->x==56||head->y==0||head->y==26)\n {\n endgamestatus=1;\n endgame();\n }\n }\n void speedup()\n{\n if(sleeptime>=50)\n {\n sleeptime=sleeptime-10;\n add=add+2;\n }\n}\n \nvoid speeddown()\n{\n if(sleeptime<350)\n {\n sleeptime=sleeptime+30;\n add=add-2;\n if(sleeptime==350)\n {\n add=1;\n }\n }\n}\n \n void snakemove()\n{\n snake nexthead;\n cantcrosswall();\n nexthead=(snake)malloc(sizeof(snake));\n if(status==U)\n {\n nexthead->x=head->x;\n nexthead->y=head->y-1;\n nexthead->next=head;\n head=nexthead;\n q=head;\n if(nexthead->x==food->x&&nexthead->y==food->y)\n {\n while(q!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n score=score+add;\n speedup();\n createfood();\n }\n else\n {\n while(q->next->next!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n gotoxy(q->next->x,q->next->y);\n color(3);\n printf("■");\n free(q->next);\n q->next=NULL;\n }\n \n }\n if(status==D)\n {\n nexthead->x=head->x;\n nexthead->y=head->y+1;\n nexthead->next=head;\n head=nexthead;\n q=head;\n if(nexthead->x==food->x&&nexthead->y==food->y)\n {\n while(q!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n score=score+add;\n speedup();\n createfood();\n }\n else\n {\n while(q->next->next!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n gotoxy(q->next->x,q->next->y);\n color(3);\n printf("■");\n free(q->next);\n q->next=NULL;\n }\n }\n if(status==L)\n {\n nexthead->x=head->x-2;\n nexthead->y=head->y;\n nexthead->next=head;\n head=nexthead;\n q=head;\n if(nexthead->x==food->x&&nexthead->y==food->y)\n {\n while(q!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n score=score+add;\n speedup();\n createfood();\n }\n else\n {\n while(q->next->next!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n gotoxy(q->next->x,q->next->y);\n color(3);\n printf("■");\n free(q->next);\n q->next=NULL;\n }\n }\n if(status==R)\n {\n nexthead->x=head->x+2;\n nexthead->y=head->y;\n nexthead->next=head;\n head=nexthead;\n q=head;\n if(nexthead->x==food->x&&nexthead->y==food->y)\n {\n while(q!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n score=score+add;\n speedup();\n createfood();\n }\n else\n {\n while(q->next->next!=NULL)\n {\n gotoxy(q->x,q->y);\n color(14);\n printf("★");\n q=q->next;\n }\n gotoxy(q->next->x,q->next->y);\n color(3);\n printf("■");\n free(q->next);\n q->next=NULL;\n }\n}\n if(biteself()==1)\n {\n endgamestatus=2;\n endgame();\n }\n}\nvoid keyboardcontrol()\n{\n status=R;\n while(1)\n {\n scoreandtips();\n if(GetAsyncKeyState(VK_UP)&&status!=D)\n {\n status=U;\n }\n else if(GetAsyncKeyState(VK_DOWN)&&status!=U)\n {\n status=D;\n }\n else if(GetAsyncKeyState(VK_LEFT)&&status!=R)\n {\n status=L;\n }\n else if(GetAsyncKeyState(VK_RIGHT)&&status!=L)\n {\n status=R;\n }\n if(GetAsyncKeyState(VK_SPACE))\n {\n while(1)\n {\n Sleep(300);\n if(GetAsyncKeyState(VK_SPACE))\n {\n break;\n }\n }\n }\n else if(GetAsyncKeyState(VK_ESCAPE))\n {\n endgamestatus=3;\n break;\n }\n else if(GetAsyncKeyState(VK_F1))\n {\n speedup();\n }\n else if(GetAsyncKeyState(VK_F2))\n {\n if(sleeptime<350)\n {\n sleeptime=sleeptime+30;\n add=add-2;\n if(sleeptime==350)\n {\n add=1;\n }\n }\n }\n Sleep(sleeptime);\n snakemove();\n }\n}\n \nvoid lostdraw()\n{\n system("cls");\n int i,j;\n gotoxy(17,5);\n color(11);\n printf("+------------------------");\n \n gotoxy(35,5);\n color(14);\n printf("o00o");\n \n gotoxy(39,5);\n color(11);\n printf("----------");\n \n gotoxy(48,5);\n color(14);\n printf("---");\n \n gotoxy(51,5);\n color(11);\n printf("----------");\n \n gotoxy(61,5);\n color(14);\n printf("o00o");\n \n gotoxy(65,5);\n color(11);\n printf("-----------------+ ");\n \n for(i=6;i<=19;i++)\n {\n gotoxy(17,i);\n printf("|");\n gotoxy(82,i);\n printf("|");\n }\n gotoxy(17,20);\n printf("+----------------------------------");\n \n gotoxy(52,20);\n color(11);\n printf("-----------------------------+");\n }\n \n void endgame()\n {\n system("cls");\n if(endgamestatus==1)\n {\n lostdraw();\n gotoxy(35,9);\n color(12);\n printf("撞墙。游戏结束！");\n }\n else if(endgamestatus==2)\n {\n lostdraw();\n gotoxy(35,9);\n color(12);\n printf("对不起，您咬到自己了。游戏结束！");\n }\n else if(endgamestatus==3)\n {\n lostdraw();\n gotoxy(40,9);\n color(12);\n printf("您结束了游戏。");\n }\n gotoxy(43,12);\n color(13);\n printf("您的得分是 %d",score);\n if(score>=highscore)\n {\n color(10);\n gotoxy(33,16);\n printf("创新纪录啦！你真棒！！！");\n file_in();\n }\n choose();\n }\n void file_in()\n {\n FILE *fp;\n fp=fopen("save.txt","w+");\n fprintf(fp,"%d",score);\n fclose(fp);\n }\n void choose()\n {\n int n;\n gotoxy(25,23);\n color(12);\n printf("重玩一局-------1");\n gotoxy(52,23);\n printf("不玩了，退出-------2");\n gotoxy(46,25);\n color(11);\n printf("选择：");\n scanf("%d",&n);\n switch(n)\n {\n case 1:\n system("cls");\n score=0;\n sleeptime=200;\n add=10;\n printsnake();\n wlcome();\n break;\n case 2:\n exit(0);\n break;\n default:\n gotoxy(35,27);\n color(12);\n printf("输入有误，请重输");\n system("pause >nul");\n endgame();\n choose();\n break;\n }\n }\n void explation()\n {\n int i,j=1;\n system("cls");\n color(13);\n gotoxy(44,3);\n printf("游戏说明");\n color(2);\n for(i=6;i<=22;i++)\n {\n for(j=20;j<=75;j++)\n {\n gotoxy(j,i);\n if(i==6||i==22)printf("=");\n else if(j==20||j==75)printf("||");\n }\n }\n color(3);\n gotoxy(30,8);\n printf("1、不能穿墙、咬到自己");\n color(3);\n gotoxy(30,8);\n printf("1、不能穿墙、咬到自己");\n color(10);\n gotoxy(30,11);\n printf("2、用↑↓←→控制蛇移动");\n color(14);\n gotoxy(30,14);\n printf("3、F1加速，F2减速");\n color(11);\n gotoxy(30,17);\n printf("4、按空格暂停，再按继续");\n color(4);\n gotoxy(30,20);\n printf("5、ESC：退出，space：暂停");\n getch();\n system("cls");\n printsnake();\n wlcome();\n }\n\n\n在贪食蛇程序中，创建食物的函数是createfood()。在这个函数中，会生成一个随机的坐标作为食物的位置，并判断这个位置是否与蛇身的位置重叠。如果重叠，则重新生成一个坐标，直到找到一个不重叠的位置。如果循环过程中一直找不到不重叠的位置，那么就会出现没有食物的情况。\n\n可能导致没有食物的情况的原因有：\n1. 蛇身的位置占据了地图的大部分空间，导致随机生成的食物位置几乎都与蛇身重叠。\n2. 循环生成食物的次数太少，导致很难找到一个不重叠的位置。\n3. 生成食物的算法有问题，无法正确判断食物是否与蛇身重叠。\n\n为了解决这个问题，可以尝试以下方法：\n1. 增加地图的大小，使蛇身占据的空间较小，增加随机生成食物位置不重叠的概率。\n2. 增加循环生成食物的次数，或者改变生成食物的算法，使得能更容易找到一个不重叠的位置。\n3. 修改生成食物的算法，确保生成的食物位置与蛇身不重叠。可以通过遍历蛇身的坐标，判断生成的食物位置是否与蛇身重叠，如果重叠，则重新生成一个位置。\n\n通过以上方法，可以解决没有食物的情况。