Find First and Second Biggest In An Array, Without Sorting It: C

We assume that a[0] has first biggest and a[1] has the second biggest value.

Now check if this assumption is correct, if not, swap the values.

 if( sbig > fbig )
 {
    temp = sbig;
    sbig = fbig;
    fbig = temp;
 }

Now since we have already checked with a[0] and a[1], we start the comparison from a[2], till N.

for(i=2; i  fbig)
  {
  sbig = fbig;
  fbig = a[i];
  }
  else if(a[i] > sbig)
  sbig = a[i];

Now, if a[i] contains a number which is bigger than fbig, we transfer the value of a[i] to fbig and the value present in fbig to sbig;
If the value of a[i] is not bigger than fbig, then we check it with sbig. If a[i] is bigger than sbig, then we assign the value of a[i] to sbig.

This way, at the end of the loop fbig will have the first biggest and sbig will have the second biggest element/number in the array.

Video Tutorial: Find First and Second Biggest In An Array, Without Sorting It: C

Full source code

#include 
#include 

void main()
{
 int a[20], N, i, fbig, sbig, temp;
 clrscr();

 printf("Enter array limit\n");
 scanf("%d", &N);

 printf("Enter %d array elements\n", N);
 for(i=0; i  fbig )
 {
    temp = sbig;
    sbig = fbig;
    fbig = temp;
 }

 for(i=2; i  fbig)
  {
  sbig = fbig;
  fbig = a[i];
  }
  else if(a[i] > sbig)
  sbig = a[i];

  printf("First Big is %d and Second big is %d", fbig, sbig);

  getch();

}

Output:
Enter array limit
6
Enter 6 array elements
99
108
777
723
786
999
First Big is 999 and Second big is 786