How can we find second maximum from array efficiently?

Question

Is it possible to find the second maximum number from an array of integers by traversing the array only once?

As an example, I have a array of five integers from whi

Answer 1

// Set the first two different numbers as the maximum and second maximum numbers

 int max = array[0];
 int i = 1;
//n is the amount of numbers

 while (array[i] == max && i < n) i++;
 int sec_max = array[i];
 if( max < sec_max ) {
    tmp = sec_max;
    sec_max = max;
    max = tmp;
 }

//find the second maximum number

 for( ; i < n; ++i ) {
   if( array[i] > max ) {
     sec_max = max;
     max = array[i];
   } else if( array[i] > sec_max && array[i] != max ) {
     sec_max = array[i];
   }
 }
 printf("The second maximum number is %d\n", sec_max);