Task: Water collected between towers

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

int getWater(int* arr,int start,int end,int cutoff){
	int i, sum = 0;
	
	for(i=start;i<=end;i++)
		sum += ((arr[cutoff] > arr[i])?(arr[cutoff] - arr[i]):0);
	
	return sum;
}

int netWater(int* arr,int size){
	int i, j, ref1, ref2, marker, markerSet = 0,sum = 0;
	
	if(size<3)
		return 0;

	for(i=0;i<size-1;i++){
		start:if(i!=size-2 && arr[i]>arr[i+1]){
				ref1 = i;
				
				for(j=ref1+1;j<size;j++){
					if(arr[j]>=arr[ref1]){
						ref2 = j;
						
						sum += getWater(arr,ref1+1,ref2-1,ref1);

						i = ref2;
						
						goto start;
					}
					
					else if(j!=size-1 && arr[j] < arr[j+1] && (markerSet==0||(arr[j+1]>=arr[marker]))){
						marker = j+1;
						markerSet = 1;
					}
				}
				
				if(markerSet==1){
					sum += getWater(arr,ref1+1,marker-1,marker);

					i = marker;
					
					markerSet = 0;
					
					goto start;
				}
			}
		}
	
	return sum;
}

int main(int argC,char* argV[])
{
	int *arr,i;
	
	if(argC==1)
		printf("Usage : %s <followed by space separated series of integers>");
	else{
		arr = (int*)malloc((argC-1)*sizeof(int));
		
		for(i=1;i<argC;i++)
			arr[i-1] = atoi(argV[i]);

		printf("Water collected : %d",netWater(arr,argC-1));
	}
	
	return 0;
}











Ada: with Ada.Text_IO;

procedure Water_Collected is

   type Bar_Index     is new Positive;
   type Natural_Array is array (Bar_Index range <>) of Natural;

   subtype Bar_Array   is Natural_Array;
   subtype Water_Array is Natural_Array;

   function Flood (Bars : Bar_Array; Forward : Boolean) return Water_Array is
      R : Water_Array (Bars'Range);
      H : Natural := 0;
   begin
      if Forward then
         for A in R'Range loop
            H     := Natural'Max (H, Bars (A));
            R (A) := H - Bars (A);
         end loop;
      else
         for A in reverse R'Range loop
            H     := Natural'Max (H, Bars (A));
            R (A) := H - Bars (A);
         end loop;
      end if;
      return R;
   end Flood;

   function Fold (Left, Right : Water_Array) return Water_Array is
      R : Water_Array (Left'Range);
   begin
      for A in R'Range loop
         R (A) := Natural'Min (Left (A), Right (A));
      end loop;
      return R;
   end Fold;

   function Fill (Bars : Bar_Array) return Water_Array
   is (Fold (Flood (Bars, Forward => True),
             Flood (Bars, Forward => False)));

   function Sum_Of (Bars : Natural_Array) return Natural is
      Sum : Natural := 0;
   begin
      for Bar of Bars loop
         Sum := Sum + Bar;
      end loop;
      return Sum;
   end Sum_Of;

   procedure Show (Bars : Bar_Array) is
      use Ada.Text_IO;
      Water : constant Water_Array := Fill (Bars);
   begin
      Put ("The series: [");
      for Bar of Bars loop
         Put (Bar'Image);
         Put (" ");
      end loop;
      Put ("] holds ");
      Put (Sum_Of (Water)'Image);
      Put (" units of water.");
      New_Line;
   end Show;

begin
   Show ((1, 5, 3, 7, 2));
   Show ((5, 3, 7, 2, 6, 4, 5, 9, 1, 2));
   Show ((2, 6, 3, 5, 2, 8, 1, 4, 2, 2, 5, 3, 5, 7, 4, 1));
   Show ((5, 5, 5, 5));
   Show ((5, 6, 7, 8));
   Show ((8, 7, 7, 6));
   Show ((6, 7, 10, 7, 6));
end Water_Collected;