Finding Maximum Subset Sum

Given an array of integers, find the maximum subset sum. 

For example, if the array is, 4 5 6 -2 3 4 -10 1 2 3, then the maximum sum is 20, and the range is 0 to 5.

If the array is, 1 2 3 -10 4 5 6 -2 3 4, then the maximum sum is 20, and the range is 4 to 9.

#include<stdio.h>
main()
{
 int i, n;
 int a[100];
 int start=-1, end=-1, sum=0;
 int maxstart=-1, maxend=-1, maxsum=0;
 printf("Enter the count: ");
 scanf("%d", &n);
   printf("Enter the numbers\n");
 for(i=0; i<n; i++) {
  scanf("%d", &a[i]);
 }
 start = 0;
 end = 0;
 for(i=0; i<n; i++) {
  sum += a[i];
  end = i;
  if(sum < 0) {
     start = i+1;
   sum = 0;
  }
  if(sum > maxsum) {
   maxstart = start;
   maxend = end;
   maxsum = sum;
  }
 }
 printf("sum = %d\nstart = %d\nend = %d\n", maxsum, maxstart, maxend);
  }