In Q4 and Q5

One mistake about the usage of "if" "for" or "=", reduce 2 points.
If the same mistake repeats, just reduce points once.


4
(a)
int max_position(float a[],int start,int end)
Miss start and end here, reduce 2 points
{
        int i,pos;
        float max;
        if(start>end)
        {
                return -1;
        }
        max = a[start];
        pos = start;
------------------------------------------------------------3 points
        for(i = start ; i <= end ; i++)
------------------------------------------------------------2 points
        {
                if(max < a[i])
------------------------------------------------------------5 points
                {
                        max = a[i];
                        pos = i;
------------------------------------------------------------5 points
                }
        }
        return pos;

}
If you compare a[i] and a[i+1] instead of max and a[i], reduce 8 points.


(b)
void selection_sort(float a[],int size)
{
        int i,pos;
        float temp;
        for(i = size - 1 ; i >= 0 ; i--)
------------------------------------------------------------2 points
        {
                pos = max_position(a,0,i);
------------------------------------------------------------5 points
                temp = a[pos];
                a[pos] = a[i];
                a[i] = temp;
------------------------------------------------------------8 points
        }

}


5.

int subsequence(char s1[],char s2[],char s3[])
{
        int i,j,size;

        
        size = strlen(s1);
        for(i = 0 ; i < size ; i++)
        {
                s3[i]='0';
        }
        s3[size] = '\0';
------------------------------------------------------------5 points


        i = 0;
        j = 0;
        while(s2[i] != '\0')
        {
                if(s1[j] == '\0')                                
                {
                        return 0;
                }
                if(s1[j] == s2[i])
                {
                        i++;
                        s3[j] = '1';
                }
                j++;
        
        }
------------------------------------------------------------20 points
        return 1;

}

If the rest of the code is correct, but you return when the first match happens, reduce 10 points.
If you check whether s1 is a subsequence of s2, reduce 2 points.
If i is not changed, reduce 5 points.