所以我在C中制作一个tic tac toe游戏，我遇到了一个问题，我要求用户通过按下2撤消他们的移动。每次轮到他们，他们可以撤消移动或继续选择下一步转过来选择另一把钥匙。
它的工作原理应该如何，但我有一个问题，如果用户输入一个字母字符，程序只是反复循环说，这不是一个数字，当它检查我的GetHumanMove函数。有没有人知道如何让它停止这样做，只是说这不是一个数字一次没有它循环程序？
这是我的代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#include <windows.h>
//Tic-Tac-Toe game in C
//20/03/2019
//5x5 Board with 4 in a row to win. Also has playable AI that randomly blocks human moves.
//Also has replay function using a doubly linked list
/*
int board[49] = {
;,;, ;, ;, ;, ;, ;,
;,1, 2, 3, 4, 5 ,;,
;,6, 7, 8, 9, 10,;,
;,11,12,13,14,15,;,
;,16,17,18,19,20,;,
;,21,22,23,24,25,;,
;,;, ;, ;, ;, ;, ;,
}
*/
struct node
{
int side;
int move;
int place;
struct node * prev;
struct node * next;
};
void append(struct node **, int, int, int);
void display(struct node *);
void delete(struct node **, int);
//Constants of pieces, border and empty places
enum { NOUGHTS, CROSSES, BORDER, EMPTY };
//Constants for human/computer win or draw
enum { HUMANWIN, COMPWIN, DRAW };
const int directions[4] = { 1, 7, 6, 8 };
int moveCount = 0;
//Values of original places to play
const int ConvertTo49[25] = {
8, 9, 10,11,12,
15,16,17,18,19,
22,23,24,25,26,
29,30,31,32,33,
36,37,38,39,40
};
void append(struct node ** list, int side, int move, int place)
{
struct node *temp , *current = *list;
if(*list == NULL)
{
*list = (struct node *) malloc(sizeof(struct node));
(*list) -> prev = NULL;
(*list) -> side = side;
(*list) -> move = move;
(*list) -> place = place;
(*list) -> next = NULL;
}
else
{
while(current -> next != NULL)
current = current -> next;
temp = (struct node *) malloc(sizeof(struct node));
temp -> side = side;
temp -> move = move;
temp -> place = place;
temp -> next = NULL;
temp -> prev = current;
current -> next = temp;
}
}
void delete(struct node ** list, int num)
{
struct node *temp = *list;
while(temp != NULL)
{
if(temp -> move == num)
{
if(temp == *list)
{
*list = (*list) -> next;
(*list) -> prev = NULL;
}
else
{
if(temp -> next == NULL)
temp -> prev -> next = NULL;
else
{
temp -> prev -> next = temp -> next;
temp -> next -> prev = temp -> prev;
}
free(temp);
}
return ;
}
temp = temp -> next;
}
printf("Element %d not found in the supplied list \n\n", num);
}
//Loop through a direction until a border square is hit
int GetNumForDir(int startSq, const int dir, const int *board, const int us)
{
int found = 0;
while(board[startSq] != BORDER)
{
if(board[startSq] != us)
{
break;
}
found++;
startSq += dir;
}
return found;
}
//Loop through directions and find four in a row
int FindFourInARow(const int *board, const int ourIndex, const int us)
{
int dirIndex = 0;
int dir = 0;
int countFour = 1;
for(dirIndex = 0; dirIndex < 4; ++dirIndex)
{
dir = directions[dirIndex];
countFour += GetNumForDir(ourIndex + dir, dir, board, us);
countFour += GetNumForDir(ourIndex + dir * -1, dir * -1, board, us);
if(countFour == 4)
{
break;
}
countFour = 1;
}
return countFour;
}
//Set up board structure
void InitialiseBoard(int *board)
{
//index variable
int index;
//set whole board to border squares initially
for(index = 0; index < 49; ++index)
{
board[index] = BORDER;
}
//Set up empty squares for placing pieces
for(index = 0; index < 25; ++index)
{
board[ConvertTo49[index]] = EMPTY;
}
}
//Print the board
void PrintBoard(const int *board)
{
//index variable
int index;
//Set pieces and places
char pceChars[] = "OX| ";
printf("\n\n\n");
//Loop through and only draw the actual playable squares, leaving out the border squares
for(index = 0; index < 25; ++index)
{
//Put lines inbetween places
if(index==1 || index==2 || index==3 || index==4 ||
index==6 || index==7 || index==8 || index==9 ||
index==11 || index==12 || index==13 || index==14 ||
index==16 || index==17 || index==18 || index==19 ||
index==21 || index==22 || index==23 || index==24)
{
printf(" |");
}
//Put space at start to space out board from edge of screen
if(index==0)
{
printf(" ");
}
//Print new line every 5 places
if(index!= 0 && index==5 || index==10 || index==15 || index==20)
{
printf("\n");
printf(" -------------------");
printf("\n");
printf(" ");
}
//Print each playable piece
printf(" %c", pceChars[board[ConvertTo49[index]]]);
}
printf("\n\n");
}
//Check if board has empty spaces
int HasEmpty(const int *board)
{
int index;
for(index = 0; index < 25; ++index)
{
if(board[ConvertTo49[index]] == EMPTY) return 1;
}
return 0;
}
//Function for making move of current player
void MakeMove(int *board, const int sq, const side)
{
//set board place that either player decides
board[sq] = side;
}
void UndoMove(int *board, int sq, int side)
{
//set board place that either player decides
board[sq] = side;
}
//Help the computer find a winning move
int GetWinningMove(int *board, const int side)
{
int ourMove = -1;
int winFound = 0;
int index = 0;
for(index = 0; index < 25; ++index)
{
if(board[ConvertTo49[index]] == EMPTY)
{
ourMove = ConvertTo49[index];
board[ourMove] = side;
if(FindFourInARow(board, ourMove, side) == 4)
{
winFound = 1;
}
board[ourMove] = EMPTY;
if(winFound == 1)
{
return ourMove;
}
ourMove = -1;
};
}
return ourMove;
}
//Get computer player move
int GetComputerMove(int *board, const int side)
{
int index;
int numFree = 0;
int availableMoves[25];
int randMove = 0;
//Set random number to randomly run a function
int randFunction = 0;
randFunction = (rand() % 2);
//Go for the winning move
randMove = GetWinningMove(board, side);
if(randMove != -1)
{
return randMove;
}
//If random function is 1, stop any winning move from the human
if(randFunction == 1)
{
randMove = GetWinningMove(board, side ^ 1);
if(randMove != -1)
{
return randMove;
}
}
randMove = 0;
//Loop through all squares and put piece in random place
for(index = 0; index < 25; ++index)
{
if(board[ConvertTo49[index]] == EMPTY)
{
availableMoves[numFree++] = ConvertTo49[index];
};
}
randMove = (rand() % numFree);
return availableMoves[randMove];
}
//Get human player move
int GetHumanMove(const int *board)
{
//Array for user input
int userInput;
char term;
//Start moveOK at 0
int moveOK = 0;
int move = -1;
//Loop through until move being made is valid
while(moveOK == 0)
{
printf("\n");
//Ask user for input of 1-9
printf("Please enter a place on the board to make your move, from 1 to 25: ");
//Make sure that user doesnt enter long string with number on the end that eventaully passes tests in the while loop
scanf("%d%c", &userInput, &term);
if(term != '\n')
{
move = -1;
printf("This is not a number\n");
continue;
}
//Check if input is in proper range
if(userInput < 1 || userInput > 25)
{
move = -1;
printf("Invalid Range\n");
continue;
}
//decrement move to get the array location of the playable places
userInput--;
//Check if place selected is already taken
if(board[ConvertTo49[userInput]] != EMPTY)
{
move = -1;
printf("Square not available\n");
continue;
}
//Set move ok to 1 after passing all the tests
moveOK = 1;
}
//Print move being made and return it
printf("\nHuman making Move at square: %d\n",(userInput+1));
return ConvertTo49[userInput];
}
//Run Game function
void RunGame()
{
struct node *list;
list = NULL;
//Display
printf("\n\n Noughts And Crosses Game:");
printf("\n =========================");
//game over variable
int gameOver = 0;
//Start on noughts side
int side = NOUGHTS;
//Record last move
int lastMoveMade = 0;
//Create new board
int board[49];
//Count of first move
int initialMove = 0;
//Initialise the Board
InitialiseBoard(&board[0]);
//Print the board to screen
PrintBoard(&board[0]);
//While game isn't over
while(!gameOver)
{
initialMove++;
//Human
if(side==NOUGHTS)
{
//Ask to undo move after first move played
if(initialMove > 1)
{
while(list -> prev != NULL)
list = list -> prev;
int undo;
printf("\n\nWould you like to undo your move? \nEnter 2 to undo or any other key/s to continue: ");
scanf("%d", &undo);
if( undo == 2)
{
while(list -> next != NULL)
list = list -> next;
char pceChars[] = "OX| ";
//printf(" %c", pceChars[board[ConvertTo49[index]]]);
int count = 2;
while(count != 0)
{
UndoMove(&board[0], list -> place, EMPTY);
list = list -> prev;
delete(&list, list -> next -> move);
moveCount--;
count--;
}
PrintBoard(&board[0]);
}
}
//Make new move for human
lastMoveMade = GetHumanMove(&board[0]);
MakeMove(&board[0], lastMoveMade, side);
moveCount++;
int humanMove;
//Find the position the computer is making on the 5x5 board
for(humanMove = 0; humanMove < 25; ++humanMove)
{
if(ConvertTo49[humanMove] == lastMoveMade)
{
break;
}
}
append(&list, 0, moveCount, lastMoveMade);
side = CROSSES;
}
//Computer
else
{
//Make move for computer
lastMoveMade = GetComputerMove(&board[0], side);
MakeMove(&board[0], lastMoveMade, side);
int compMove;
//Find the position the computer is making on the 5x5 board
for(compMove = 0; compMove < 25; ++compMove)
{
if(ConvertTo49[compMove] == lastMoveMade)
{
break;
}
}
printf("\nComputer making move at square: %d", compMove+1);
moveCount++;
append(&list, 1, moveCount, lastMoveMade);
side = NOUGHTS;
PrintBoard(&board[0]);
}
//If three in a row exists, game over
if(FindFourInARow(board, lastMoveMade, side ^ 1) == 4)
{
gameOver = 1;
if(side == NOUGHTS)
{
printf("\nGame Over!\n");
printf("Computer Wins! :(\n");
}
else
{
PrintBoard(&board[0]);
printf("\nGame Over!\n");
printf("Human Wins! :D\n");
}
}
//If no more moves, game is a draw
if(!HasEmpty(board))
{
PrintBoard(&board[0]);
printf("\n\nGame Over!\n");
gameOver = 1;
printf("It's a draw! :/\n");
}
}
/*
*
* Match Replay
*
*/
int answer;
printf("\n\nWould you like to replay the match? \nEnter 1 to replay or any other key/s to quit: ");
scanf("%d", &answer);
if(answer == 1)
{
InitialiseBoard(&board[0]);
while ( list != NULL )
{
MakeMove(&board[0], list -> place, list -> side);
PrintBoard(&board[0]);
char who[7];
if(list -> side == 0)
{
strcpy(who, "NOUGHTS");
//who = "NOUGHTS";
}
else
{
strcpy(who, "CROSSES");
//who = "CROSSES";
}
int moveMade;
//Find the position the computer is making on the 5x5 board
for(moveMade = 0; moveMade < 25; ++moveMade)
{
if(ConvertTo49[moveMade] == list -> place)
{
break;
}
}
printf ("\nMove:%2d Side:%8s Place: %d\n", list -> move, who, moveMade+1);
Sleep(2000);
list = list -> next ;
}
}
else
{
printf("\nGood Game! See ya!\n");
getch();
}
}
int main()
{
//Create random number
srand(time(NULL));
//Call Run Game to play
RunGame();
return 0;
}
scanf不会消耗与您的格式不匹配的输入。它保留在输入流中。因此，当您键入一个字母时，它无法匹配您想要的数字%d并保留在输入流中。
scanf("%d%c", &userInput, &term);
使用scanf来消耗整个输入线会更简单，而不是getline。然后使用sscanf（函数的基于字符串的版本）或其他方法解析结果。
char *line = NULL;
size_t len = 0;
while ((read = getline(&line, &len, stdin)) != -1) {
// Do something with line
int scanned = sscanf(line, "%d%c", &userInput);
if (scanned == EOF || scanned != 2) {
printf("Line failed to match\n");
}
}
只需阅读手册页：
The format string consists of a sequence of directives which describe
how to process the sequence of input characters. If processing of a
directive fails, no further input is read, and scanf() returns. A
"failure" can be either of the following: input failure, meaning that
input characters were unavailable, or matching failure, meaning that
the input was inappropriate (see below).
你没有检查scanf()的返回值。因此，您尝试始终扫描相同的非数字作为数字。