Array Sorting Issues in C-CodePudding

I am trying to make a program that sorts an array without using the sort function (that won't work with objects or structs). I have made the greater than one work, but the less than one keeps changing the greatest element in the array to a one and sorting it wrong, and when used with the greater than function, the first element is turned into a large number. Can someone please help me fix this or is it my compiler.

void min_sort(int array[], const unsigned int size){
    for(int k = 0; k < size; k  ) {
        for(int i = 0; i < size; i  ) {
            if(array[i] > array[i 1]){
                int temp = array[i];
                array[i] = array[i 1];
                array[i 1] = temp;
            }
         }
     }
}

CodePudding user response：

You are not looping correctly. Looks like you are trying bubble sort which is:

void min_sort(int array[], const unsigned int size){
    for(int k = 0; k < size; k  )
        for(int i = k 1; i < size; i  )
            if(array[i] < array[k]){
                int temp = array[i];
                array[i] = array[k];
                array[k] = temp;
            }
}

CodePudding user response：

void min_sort(int array[], const unsigned int size)
{
  for(int i=0;i<size-1;i  )
  {
    for(int j=0;j<size-1-i;j  )
    {
      if(array[j]>array[j 1])
      {
        swap(array[j] , array[j 1]);
      }
    }
  }
}

I see that you are trying to implement the bubble sort algorithm. I have posted the code for bubble sort here. In bubble sort you basically compare the element at an index j and the element next to it at index j 1. If array[j] is greater than array[j 1] , you swap them using the swap() function or by using the temp method. The outer loop will run size - 1 times , and the inner loop will run size - 1 - i times because the last element will already be in place.

For Example we have an array of size 4 with elements such as :

array[i] = [100,90,8,10]

The bubble sort will sort it in the following steps :

90,100,8,10 90,8,100,10 90,8,10,100

8,90,10,100 8,10,90,100

8,10,90,100

See, the use of size-1-i . You can see the nested loop runs less number of times in each iteration of the outer loop.

CodePudding user response：

Your attempt at bubble sort is basically correct, you just have an out of bounds issue with your inner loop. During the inner loop's last run, i == size - 1, therefore i 1 is equal to size, thus data[i 1] is out of range. Simply change the condition of your for to be i < size - 1.

Working example: https://godbolt.org/z/e5ohWPfTz