c - C中的冒泡排序。输出与输入相同

Question

作为一项学校作业，我们正在用 c 语言编写一个冒泡排序程序。我写的代码有效。唯一的问题是输出返回输入而不返回交换的输入。我有点卡住了。无论我做什么，我要么出错，要么什么都没有改变。有人知道出了什么问题吗？任何帮助将不胜感激!!

#include <stdio.h>
#include <string.h>
#define MAXLENGTH 100      


void getString(char *str);  
void printResult(char *str);
int greaterThan(char ch1, char ch2); 
void swap(char *str, int index1, int index2);  


int main(void) {
int len;                  // length of the entered string
char str[MAXLENGTH];      // input should be no longer than MAXLENGTH


getString(str);
len = strlen(str);  // get length of the string, from sting.h
int j;
for (j = 0; j < len-j; j++) {  
    int i;
    for (i = 0; i < len-j; i++){    
        char ch1 = str[i];  
        char ch2 = str[i+1];    
        if (greaterThan(ch1, ch2)) {    
            swap(str, i, i+1);  // swap char 1
            swap(str, i, i+1);  // swap char 2
        }
    }
}
printResult(str);

return(0);
}



void getString(char *str) {    
    printf("Enter the string you would like to sort: ");  
    scanf("%s",str);   
    }


void printResult(char *str){    
    printf("Here is the sorted string: ");  
    printf("%s",str);   
}


int greaterThan(char ch1, char ch2){    
    return (ch1 > ch2);
}


void swap(char *str, int index1, int index2){   
    char h =  str[index1];  
    str[index1] = str[index2];  
    str[index2] = h;    
}

Answer 1

试试这个:

getString(str);
len = strlen(str);  // get length of the string, from sting.h
int j;
for (j = 0; j < len-j; j++) {  
    int i;
    for (i = 0; i < len-j; i++){    
        char ch1 = str[i];  
        char ch2 = str[i+1];    
        if (greaterThan(ch1, ch2)) {    
            swap(str, i, i+1);  // swap char 1
        }
    }
}
printResult(str);

return(0);
}