什麼導致這個奇怪的輸出？

Question

我有以下代碼：

void doPlayerMove(void) 
{ 
    bool moved = false; 

    while (!moved) 
    { 
     printf("\nWhere is the piece you want to move?(rc):"); 
     int r = getchar() - '0';// gets the row number 
     int c = getchar() - '0';// gets the column number 

     printf("%d:%d", r, c);// prints the chosen row/column 

     clearInput(); 
     printf("\nWhere is the space you want to move to?(rc):"); 
     int r2 = getchar() - '0'; 
     int c2 = getchar() - '0'; 

     printf("%d:%d", r2, c2); 

     ... 
    } 
} 

void clearInput(void) 
{ 
    while(getchar() != '\n'); 
} 

這是輸出我得到：

Where is the piece you want to move?(rc):51 
5:1 
Where is the space you want to move to?(rc):40 
4:00 

怎麼了額外的0？有沒有人看到問題在哪裏？

Answer 1

由於OP說，在註釋：

問題解決了，它是從一些功能我是在 調用一些輸出...抱歉虛驚一場！