Can someone plz tell me why i am getting WA ! which test case i am missing ?
https://www.codechef.com/viewsolution/26554850
How my solution is wrong ?
> #include<iostream>
> #include<stack>
> #include<vector>
> using namespace std;
>
> int main()
> {
> int t;
> vector<int> ans;
> cin>>t;
> while(t--)
> {
> stack<char> expr;
> string str;
> cin>>str;
> int sum=0;
> for(int i=0;i<str.length();i++)
> {
> if(str[i]=='<')
> expr.push(str[i]);
> else if(!expr.empty())
> {
> expr.pop();
> sum+=2;
> }
> else
> break;
> }
> ans.push_back(sum);
> }
> for(auto i=ans.begin();i!=ans.end();i++)
> cout<<*i<<"\n";
> return 0;
> }
>
The answer is correct. It should be 0, since there are no "lapin"s at the prefix.
Can anyone tell what’s wrong with this code?
#include <iostream>
#include <vector>
#include <stack>
using namespace std;
#define ull unsigned long long int
int getK(vector<char> s) {
stack<char> st;
int k=0;
for(int i=0; i<s.size(); i++) {
if(s[i]=='<') {
st.push('<');
}
else { // '>'
if(!st.empty()) {
st.pop();
k++;
}
else {
break;
}
}
}
return k;
}
int main() {
int T;
cin >> T;
while(T--) {
string ss;
cin >> ss;
vector<char> s(ss.begin(),ss.end());
int K = getK(s);
if(K==getK(vector<char>(ss.begin()+1,ss.end()))) cout << 0 << endl;
else cout << K*2 << endl;
}
}
can anyone plz say why this is giving WA ?? Any particular case
Consider the testcase:
1
<<>
Kindly check why this is giving WA.
My logic : If ‘<’ increase top pointer. If ‘>’ decrease top pointer and increase length by 2 (1 for < and 1 for >)
Initial top pointer value = -1. If ‘>’ and top pointer is -1 it means no matching ‘<’ encountered…so return the current length of valid string till now.
Solution : CodeChef: Practical coding for everyone
Your solution fails on the testcase in the post above yours
Yours is the only solution that I understood properly. Thanks for sharing!
I tried solving this problem with implementing concept of stack but it is giving WA. Although in my PC’s IDE it worked well.
Please once check my solution(CodeChef: Practical coding for everyone) it’s small.
Thank you so much sir.
Thanks. I saw your post but forgot to reply. today i just happened to pass by and noticed it
I think <<> should give 0 ?
Yep
Solution adjusted accordingly…but still getting WA for some test case…Can you visualise any such case?
CodeChef: Practical coding for everyone.
MW it passed the <<> case
Consider the test input:
1
<><
///maybe this is what you asked
#include <bits/stdc++.h>
#include
#include
#define ll long long int
using namespace std;
bool func(string s,int i,int j)
{
stack<char> stk;
for(;i<=j;i++)
{
if(s[i]=='<')
stk.push(s[i]);
else
{ if(stk.empty()||stk.top()!='<')
return false;
else
stk.pop();
}
}
return stk.empty();
}
int main() {
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int t;cin>>t;
while(t–)
{
string s;
cin>>s;
stack stk;
vector v;
for(int i=0;i<s.length();i++)
{
if(s[i]=='<')
{
for(int j=i+1;j<s.length();j++)
{
if(s[j]=='>')
{
if(func(s,i,j)==true)////if(func(s,i+1,j-1)==true)
v.push_back(j-i+1);
}
}
}
}
if(v.size()==0)
cout<<"0\n";
else
cout<<*max_element(v.begin(),v.end())<<"\n";
}
}
Can anyone please explain what is longest prefix length means it’s confusing please break it in simple terms.
Thanks