Output not coming

#1

#include
using namespace std;
int main() {
int n,water=0,maxl,maxr,i,j;
cin>>n;
int *arr = new int[n];
int *arr1 = new int[n];
int *arr3 = new int[n];
for(int i=0;i<n;i++)
{
cin>>arr[i];
}
maxl = arr[0];
for( i=1,j=0;i<n&&j<n;i++,j++)
{
if(arr[i]>maxl)
{
maxl=arr[i];
arr1[j] = maxl;

	}
}
maxr=arr[n-1];
for( i=n-2,j=n-1;i>=0&&j>=0;i--,j--)
{
	if(arr[i]>maxr)
	{
		maxr=arr[i];
		arr3[j] = maxr;
	}
}
for( j=0;j<n;j++)
{
	if(arr1[j]<arr3[j])
	water =water +( arr1[j] - arr[i] );
	else
	water = water +(arr3[j]-arr[i]);
}
cout<<water;  


return 0;

}

#2

hello Supratik,
what error u are getting?

#3

I am getting output as 0

#4

In your arr1 array , arr1[i] is maximum element value from 0 to i right?
and In your arr3 array , arr3[i] is maximum element value from i to n-1 right?

#5

yes arr1 is maximum from left to right and arr3 is maximum from right to left

#6

@supratik260699 hey check out this code i have made some changes - https://ide.codingblocks.com/s/173001

#7

errors-

  1. in ur last loop if u see u are subtracting arr[i] but it should be arr[j]
    i.e water=water + (arr1[j]-arr[j])

  2. your arr1 and arr3 are not calculating correct values so i have made it simple
    if(arr[j]>maxl)
    {
    maxl=arr[j];
    }
    arr1[j] = maxl;

#8

let me know if u still have any doubt

#9

why did u didnt use i in any of the for loops for comparison of maximum value,you used j which is different array. dont we need i in any of the for loops?

#10

see it does’nt matter whether I use i or j . also we can use same variable to access different array.

apart from this problem i want to give u another problem.
you are given an array and you need to store maximum from left to right in another array.
can u please write a program for this and share it here.
example

size 5
array 4 1 8 9 2

output 4 4 8 9 9
array

#11

ok i am giving it to you

#12

#include
using namespace std;
int main()
{
int n,max;
cin>>n;
int *arr = new int[n];
for(int i=0;i<n;i++)
{
cin>>arr[i];
}
max = arr[0];
for(int i=0;i<n;i++)
{
if(arr[i]>arr[0])
{
max = arr[i];
}
cout<<max<<" ";
}

}

#13

check ur if statement do you think is it correct?

#14

is there any other approach better than this beacuse i have done all the program of finding maximum like this only

#15

for linear non sorted array above one is the only approach.also your code is not correct

#16

your if statement should be like
if(arr[i]>max])
{
max = arr[i];
}

#17

can u plz tell me what is wrong bcoz output is coming correctly

#19

check your code output for this
size 5
array 4 1 9 8 2

#20

O I have understood about the mistake it should be if(arr[i]>max)

#21

ok so are u confident ?