Thank you for replying !! Here is the link to my submission:-CodeChef: Practical coding for everyone
Thanks - your submission fails for the following testcase:
1
abba
How did you check this?
i mean how did you know the reason for rejection of my submission!!
I usually write a testcase generator for the problems I solve - I droned on about the process here. It was then a simple matter to check the output from your program against known-correct answers to random testcases until one failed
Edit:
To be clear - I donāt know if Codechef run that particular abba
testcase, but itās definitely a testcase that exposes a flaw in your program
Okay thank you my friend for helping me out and teaching me new stuff. I have successfully removed that flaw from my code and tried to resubmit but still my submission gets rejected and its very frustrating. Here is the link of my new submission CodeChef: Practical coding for everyone
Please have a look in it.
This fails on
1
abbbabbab
I suggest re-reading the Problem very carefully, as your current approach isnāt going to work
Okay thank you for helping me !!
thanks once again ssjgz can u tell me how to generate testcases
Hereās lapindrome complete with testcase generator:
// Simon St James (ssjgz) - 2019-10-29
//
// Solution to: https://www.codechef.com/problems/LAPIN
//
#include <iostream>
#include <array>
#include <cassert>
#include <sys/time.h> // TODO - this is only for random testcase generation. Remove it when you don't need new random testcases!
using namespace std;
template <typename T>
T read()
{
T toRead;
cin >> toRead;
assert(cin);
return toRead;
}
constexpr auto numLetters = 26;
array<int, numLetters> letterHistogram(const string& s)
{
array<int, numLetters> letterHistogram = {};
for (const auto letter : s)
{
letterHistogram[letter - 'a']++;
}
return letterHistogram;
}
bool isLapindrome(const string& s)
{
const int length = s.length();
const auto leftHalf = s.substr(0, length / 2);
const auto rightHalf = s.substr(length - length / 2);
return letterHistogram(leftHalf) == letterHistogram(rightHalf);
}
#if 0
SolutionType solveOptimised()
{
SolutionType result;
return result;
}
#endif
int main(int argc, char* argv[])
{
ios::sync_with_stdio(false);
if (argc == 2 && string(argv[1]) == "--test")
{
struct timeval time;
gettimeofday(&time,NULL);
srand((time.tv_sec * 1000) + (time.tv_usec / 1000));
//const int T = rand() % 100 + 1;
const int T = 1;
cout << T << endl;
for (int t = 0; t < T; t++)
{
const int len = 1 + rand() % 12;
const int maxChar = 1 + rand() % numLetters;
string s;
for (int i = 0; i < len; i++)
{
s.push_back('a' + rand() % maxChar);
}
cout << s << endl;
}
return 0;
}
const auto T = read<int>();
for (int t = 0; t < T; t++)
{
const auto s = read<string>();
cout << (isLapindrome(s) ? "YES" : "NO") << endl;
}
assert(cin);
}
To generate a testcase, just run the executable and pass it the --test
flag on the command-line e.g if the executable is called a.out
:
./a.out --test
See also:
The implementation of the logic as given in Editorial in Python3
t = int(input())
while(t>0):
d = {'a': 0, 'b': 0, 'c': 0, 'd': 0, 'e': 0, 'f': 0, 'g': 0, 'h': 0, 'i': 0, 'j': 0, 'k': 0, 'l': 0, 'm': 0, 'n': 0, 'o': 0, 'p': 0, 'q': 0, 'r': 0, 's': 0, 't': 0, 'u': 0, 'v': 0, 'w': 0, 'x': 0, 'y': 0, 'z': 0}
s = input()
ln = len(s)
fg = 0
s1 = ""
s2 = ""
if(ln % 2 == 0):
s1 = s[:ln//2]
s2 = s[ln//2:]
# print(s1, s2)
else:
s1 = s[:ln//2]
s2 = s[(ln//2)+1:]
# print(s1, s2)
for i in s1:
d[i] += 1
for j in s2:
d[j] -= 1
# print(d)
for i in d.values():
if(i != 0):
fg = 1
break
if(fg == 1):
print("NO")
else:
print("YES")
t -= 1
Consider the testcase:
5
bbcccbe
gedce
eccbdde
bdfbdbe
egafded
tnx broā¦i got itā¦i didnāt clear the map.
Even better would be to just write your code so that this kind of problem simply canāt happen in the first place; none of l
,l1
,i
,s
or m
are used outside of the while
block, so why declare them there?
#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int main() {
int t;
cin>>t;
while(t--)
{
int l,l1,i;
string s;
map<char,int> m;
cin>>s;
l=s.size()/2;
if(l==0)
{
cout<<"NO\n";
continue;
}
if(s.size()%2==0)
{
l1=l;
}
else
{
l1=l+1;
}
i=l1;
while(i<s.size())
{
if(m.find(s[i])==m.end())
{
m.insert(pair<char,int>(s[i],1));
}
else
m[s[i]]++;
i++;
}
for(i=0;i<l;i++)
{
if(m.find(s[i])==m.end()|| m[s[i]]==0)
{
cout<<"NO\n";
break;
}
else
m[s[i]]--;
}
if(i==l)
{
cout<<"YES\n";
}
}
return 0;
}
or better still:
#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int main() {
int t;
cin>>t;
while(t--)
{
string s;
cin>>s;
const int l=s.size()/2;
if(l==0)
{
cout<<"NO\n";
continue;
}
int l1 = l;
if(s.size()%2!=0)
{
l1=l + 1;
}
int i=l1;
map<char,int> m;
while(i<s.size())
{
if(m.find(s[i])==m.end())
{
m.insert(pair<char,int>(s[i],1));
}
else
m[s[i]]++;
i++;
}
for(i=0;i<l;i++)
{
if(m.find(s[i])==m.end()|| m[s[i]]==0)
{
cout<<"NO\n";
break;
}
else
m[s[i]]--;
}
if(i==l)
{
cout<<"YES\n";
}
}
return 0;
}
but there may be repeated memory allocation and memory release for themā¦ will it affect performance of code?
The construction of an empty string
or an empty map
should not involve memory allocations.
got it ā¦Thank you sirā¦
whats wrong in this solution
include<bits/stdc++.h>
using namespace std;
int main()
{
int i,j,count=0;
int t;
cin>>t;
while(tā)
{ int n;
string s;
cin>>s;
n=s.length();
if(n%2==0)
{
for(i=0;i<n/2;i++)
{
for(j=n/2;j<n;j++)
{
if(s[i]==s[j])
{
count++;
}
}
}
if(count==n/2)
cout<<"yes"<<endl;
else
cout<<"no"<<endl;
}
else if(n%2!=0)
{
for(i=0;i<n/2;i++)
{
for(j=(n+1)/2;j<n;j++)
{
if(s[i]==s[j])
{
count++;
}
}
}
if(count==n/2)
cout<<"yes"<<endl;
else
cout<<"no"<<endl;
}
}
return 0;
}
Please either format your code or (better!) link to your submission - the forum software has mangled it and it wonāt compile!