Runtime Error: Runtime ErrorSegmentation Fault (SIGSEGV) [closed] - c++

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LINK TO THE ACTUALL PROBLEM
I am trying to solve a question on codechef but getting a runtime error. Although when i executed same code on virtual studio code, no error was observed.
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin>>n;
string s[n],b;
int i=0;
while(i<n)
{
i++;
cin>>s[i];
if(i==0) b=s[0];
else {
if(b.length()<=s[i].length()) b=s[i];
}
}
cout<<b;
}
return 0;
}

Answer 1

This is because you are incrementing i and then using it for reading the string s[i], so at one point it reads for the element n+1 which is not allocated so the error that occurs here is Segmentation Error.
What you have to do is increment the i after reading the string s[i]. You can correct this by moving the i++; statement to the end of the while block.
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin>>n;
string s[n],b;
int i=0;
while(i<n){
cin>>s[i];
if(i==0)
b=s[0];
else
if(b.length()<=s[i].length())
b=s[i];
i++;
}
cout<<b;
}
return 0;
}

Answer 2

#theWellHopeErr's answer is correct and gets accepted on geeksforgeeks when the fast i/o lines are removed. I have commented them out below.
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--){
//ios_base::sync_with_stdio(false);
//cin.tie(NULL);
int n;
cin>>n;
string s[n],b;
int i=0;
while(i<n){
cin>>s[i];
if(i==0)
b=s[0];
else
if(b.length()<=s[i].length())
b=s[i];
i++;
}
cout<<b<<"\n";
}
return 0;
}
Also, string s[n] is not to be done. Always better to save memory. This can be done just by storing the max length in a variable maxLen and updating your result only when you encounter a longer string
int n;
cin>>n;
string result;
int maxLen = 0;
for(int i = 0; i < n; i++)
{
string s;
cin>>s;
if(s.length() > maxLen)
{
maxLen = s.length();
result = s;
}
}
cout<<result<<"\n";