You’re getting a runtime error on ideone because @line 8
you’re trying to read something into n
whereas the standard input is empty. If you fill stdin
with the sample input given in the question, it runs just fine and produces the correct output. Here’s the ideone link. However, when I submit your code on CodeChef, I’m bombarded with a series of WA
s. ¯\_(ツ)_/¯
I have one idea! to bypass the run time error! (if your logic is right).there are few steps you follow then i surely challenge that you didn’t get any run time error!;
step 1:
first see constraint and see test cases.
step2: then apply “if”(conditional) statement on test cases.
example: 1<T<100 (contraint)
implement this in your code then …
if(t>=1 && t<=100)
then what should i do to get it correct in codechef
is my logic correct??
Your logic appears to be a little incorrect. Here’s a list of issues:

@line 14
 The comparisona>b
doesn’t help in finding out the winner. Instead you may use this:
score[i]=score[i1]+(ab);
and if score[i]
is positive, Player 1
is the winner of round i
or else Player 2
is.

@lines 24, 25, 28
score
may store negative values butlead
must be positive, so you may use theabs
function for absolute values. 
@lines 27, 28
 You’re trying to access suspicious indices ofscore
andplayer
.
I’ve made the changes in your code with comments explaining why.
Here's the code
#include <iostream>
#include <math.h>
using namespace std;
int main()
{
long long n,x;cin>>n;
long long score[n+1];
long long player[n];
score[0]=0;
for(int i=1;i<=n;i++){
int a,b;cin>>a>>b;
/*if(a>b){*/score[i]=score[i1]/**/+(ab);
if(score[i]<0){/*score[i]=score[i]*(1);} */
player[i1]=/*1*/2; // as b is the second operand of the subtraction (ab) @line 14
}
else{/*score[i]=score[i1](ba);
if(score[i]<0){score[i]=score[i]*(1);}*/
player[i1]=/*2*/1; // as a is the first operand of the subtraction (ab) @line 14
}
} long long max = score[0];
for (int i = 1; i <= n; i++) {
// if (score[i] > max){
if (abs(score[i]) > max){ // lead is positive but score[i] may hold a negative value
// max = score[i];
max = abs(score[i]); // lead is positive but score[i] may hold a negative value
}}
for(int i=0;i</*=*/n;i++){ // player has valid indices 0, 1, 2, ..., n1
// if(max==score[i]){x=player[i1];}
if(max==abs(score[i+1])){x=player[i];} // player[i] corresponds to the score[i+1]
}
cout<< x<<" "<< max<<endl;
return 0;
}
I hope this is clear now.