Minimise Z (Coding Ninjas)

Problem statement

Given an array ‘A’. Your task is to choose any two different elements of the array say ‘X’ and ‘Y’, such that ‘Z’ is minimum possible. Where ‘Z’ = ‘X’ × ’Y’.

Return the minimum possible value of ‘Z’.

Example:

‘N’ = [5, 3, 9, 6, 3]

‘X’ can be chosen as 3(index 1) and ‘Y’ can be chosen as 3(index 4). 'Z' = 3*3 = 9.
No other combination can have a smaller value of ‘Z’.

Detailed explanation ( Input/output format, Notes, Images )

Constraints:

1 <= ‘T’ <= 10
2 <= ‘N’ <= 10^5
-10^4 <= ‘A[i]’ <= 10^4

Time Limit: 1 sec

Sample Input 1:

2
6
-6 10 -1 2 10 -1 
7
-7 5 -1 -4 -10 -8 10 

Sample Output 1:

-60
-100

Explanation of sample input 1:

For 1st Testcase :
‘X’ can be chosen as -6(index 0)  and ‘Y’ can be chosen as 10(index 1). 'Z' = -6*10 = -60.
No other combination can have a smaller value of ‘Z’.

For 2nd Testcase :
‘X’ can be chosen as -10(index 4) and ‘Y’ can be chosen as 10(index 6). 'Z' = -10*10 = -100.
No other combination can have a smaller value of ‘Z’.

Sample Input 2:

3
6
-5 -10 5 7 -8 -8 
6
-10 6 1 -6 7 5 
8
0 0 3 -8 -10 -7 4 -5 

Sample Output 2:

-70
-70
-40

Solution:

int minimiseZ (vector<int> &a){
    // Write your code here.
int mini=a[0],mini=INT_MAX;
int maxi=a[0],maxi=INT_MIN;

//Finding the minimum, second minimum, maximum and second maximum.
for(int i=1;i<a.size();i++){
  if(a[i]<=mini){
   smini=mini;
   mini=a[i];
     } 
 else if(a[i]<=smini)
 smini=a[i];
 
 if(a[i]>=maxi){
  smaxi=mini;
  mini=a[i];
    }
 else if (a[i]>=smaxi)
  smaxi=a[i];
 }
if(mini<0 && maxi>0)
 return mini*maxi;
else if(mini>0)
 return mini*smini;
else if(maxi<0)
 return maxi*smaxi;
}