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

int main() {
         int sizeOfArray;
         int *pArray = 0;
         int i, iBegin, iEnd;
         int *pFirstZero = 0;
         int *pLastNegative = 0;

         printf("Enter array size: ");
         scanf("%d", &sizeOfArray);
         pArray = (int *)malloc(sizeof(int) * sizeOfArray);
         if(!pArray) {
             printf("Something wrong. Terminate.");
             exit(0);
         }
         printf("Enter all %d values: ", sizeOfArray);
         for(i = 0; i < sizeOfArray; ++i) {
             scanf("%d", pArray + i);
         }
         iEnd = sizeOfArray - 1;
         for(iBegin = 0; iBegin <= iEnd; ++iBegin) {
             if(!pFirstZero)
                 if(pArray[iBegin] == 0)
                     pFirstZero = pArray + iBegin;
             if(!pLastNegative)
                 if(pArray[iEnd-iBegin] < 0)
                     pLastNegative = pArray + iEnd - iBegin;
         }
         if(pFirstZero && pLastNegative) {
             int temporary;
             printf("Array before:\n");
             for(i = 0; i < sizeOfArray; ++i)
                 printf("%d ", pArray[i]);
             temporary = *pFirstZero;
             *pFirstZero = *pLastNegative;
             *pLastNegative = temporary;
             printf("\nArray after:\n");
             for(i = 0; i < sizeOfArray; ++i)
                 printf("%d ", pArray[i]);
             printf("\n%d elements between\n", abs(pLastNegative - pFirstZero) - 1);
         } else {
             printf("Oops! Terminate.");
             free(pArray);
             exit(0);
         }
         free(pArray);
         return 0;
}