#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX_SIZE 1000

void populate ( int A[], int n )
{
   int i;

   for (i=0; i<n; ++i) {
      A[i] = 1 + rand() % 20;
      if (rand() % 2) A[i] = -A[i];
   }
}

void printArray ( int A[], int n )
{
   int i;

   for (i=0; i<n; ++i) {
      printf("%3d ", A[i]);
      if (i % 20 == 19) printf("\n");
   }
   if (i % 20) printf("\n");
}

void pnsep1 ( int A[], int B[], int n )
{
   int i, j, k;

   for (i=j=0, k=n-1; i<n; ++i) {
      if (A[i] < 0) B[j++] = A[i];
      else B[k--] = A[i];
   }
}

void pnsep2 ( int A[], int n )
{
   int i, j, t;

   i = 0; j = n-1;
   while (i <= j) {
      if (A[i] < 0) ++i; else {
         t = A[i]; A[i] = A[j]; A[j] = t;
         --j;
      }
   }
}

void findInd ( int A[], int n )
{
   int i, j, k, sum;

   k = 0; while ((k < n) && (A[k] < 0)) ++k;
   if ((k == 0) || (k == n)) sum = 1;
   else {
      i = k - 1; j = k; sum = A[i] + A[j];
      while (1) {
         if (sum == 0) break;
         if (sum > 0) {
            if (i == 0) break;
            sum += A[--i];
         } else {
            if (j == n-1) break;
            sum += A[++j];
         }
      }
   }
   if (sum == 0) {
      printf("i = %d, j = %d\n", i, j);
      for (k=i; k<=j; ++k) printf("%3d ", A[k]);
      printf("\n");
   } else {
      printf("No indices found...\n");
   }
}

int main ()
{
   int n, A[MAX_SIZE], B[MAX_SIZE];

   srand((unsigned int)time(NULL));
   printf("n = "); scanf("%d", &n);
   populate(A,n);
   printf("+++ Initial array A:\n"); printArray(A,n);
   pnsep1(A,B,n);
   printf("+++ New array B:\n"); printArray(B,n);
   pnsep2(A,n);
   printf("+++ Modified array A:\n"); printArray(A,n);
   printf("Array A: "); findInd(A,n);
   printf("Array B: "); findInd(B,n);
   exit(0);
}