673 - Parentheses Balance

[brianfry713]

Don't use a package. Use class Main.

[imran_12]

here is my code....i dunno why i m getting WA??
plz somebody help....

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#include<stdio.h>
#include<string.h>
int main()
{
    char a[130],c;
    int n,j,i,flag,flagn,b;
    while(scanf("%d",&n)==1)
    {
        fflush(stdin);
        for(j=1;j<=n;j++)
        {
            flag=0;
            flagn=0;
        gets(a);
        b=strlen(a);
        for(i=0;i<b;i++)
        {
            if(a[i]=='(')
            {
                flag++;
            }
            if(a[i]==')')
            {
                flag--;
            }
            if(a[i]=='[')
            {
                flagn++;
            }
            if(a[i]==']')
            {
                flagn--;
            }
        }
        if(flag==0 && flagn==0 && (a[0]=='(' && a[b-1]==')') || (a[0]=='[' && a[b-1]==']'))
        {
            printf("Yes\n");
        }
        else
        {
            printf("No\n");
        }
        fflush(stdin);
        }
    }
    return 0;
}

[brianfry713]

Don't use fflush(stdin);

[mohdali231993]

Code: Select all

#include<iostream>
#include<stack>
#include<string>
using namespace std;
typedef unsigned int uint;
int main()
{
    uint t, flag = 1, len,i;
    char c, cc;
    string ss;
    cin>>t;
    while(t)
    {    
        flag=1;stack<char> s;i=0;
        cin>>ss;
        len = ss.length();
        while(i < len)    
        {
                
            c = ss[i];  
            if((int)c == 40 || (int)c == 91)
                {s.push(c);   }
            else 
            {   
                cc = s.top();
                if((int)cc-(int)c <= 5)
                  {s.pop();}
                else
                  {flag=0;break;}       
            }   
            i++;
                
        }
        if(!s.empty()) flag=0;
        if(flag) cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
        t--;    
    }        
    return 0;
}    

I am getting a runtime error on this code
Plz help

[mohdali231993]

Code: Select all

#include<iostream>
#include<stack>
#include<string>
using namespace std;
typedef unsigned int uint;
int main()
{
    uint t, flag = 1, len,i;
    char c, cc;
    cin>>t;
    while(t)
    {    
        flag=1;stack<char> s;string ss;i=0;
        cin>>ss;
        len = ss.length();
        while(i < len)    
        {
            c = ss[i];  
            if((int)c == 40 || (int)c == 91)
                {s.push(c);}
            else 
            {   
                if(!s.empty())
                {
                 cc = s.top();
                 if(((int)c-(int)cc <= 2) && ((int)c-(int)cc > 0))
                 {s.pop();}
                 else
                 {flag=0;break;}
                }
                  else
                  {flag=0;break;}
                       
            }   
            i++;
                
        }
        if(!s.empty()) {flag=0;}
        if(flag) cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
        t--;    
    }        
    return 0;
}    
    
    
    

Ignore the last question
This code is giving WA
Help me out guys

[lighted]

Try to check input in this thread before posting

You need to parse the input line by line as a line may be blank.

Input:

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4

([])
(([()])))
([()[]()])()

Output should be:

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Yes
Yes
No
Yes

[mohdali231993]

@lighted
Thanks i figured it out
and sorry to have bothered you

[littleaich]

Dear Experts,

I have read all the discussions on this problem posted here and my code can handle the discussed problems correctly. But still I am getting wrong answer. Can anybody give any hint or some tricky test cases other than the already posted ones. Here is my code:

Code: Select all

#include <iostream>
#include <string>
#include <algorithm> 

using namespace std;

int main(void)
{
	int n, len, count, front, back;
	bool matching;
	char backTracker;
	bool getFront = false;
	cin >> n;
	fflush(stdin);
	string line;
	
	while(n!=0)
	{
		getline(cin,line);
		line.erase(std::remove(line.begin(), line.end(), ' '), line.end());
		count = 0;
		matching = true;
		len = line.length();
		if(line.empty())
			matching = true;
		else if((len%2!=0) | (line[0]==')') | 
			(line[0]==']') | (line[len-1]=='(') | (line[len-1]=='['))
			matching = false;
		else
		{
			front = len;
			while(front>0)
			{
				if(line[front-1]=='(')
				{	
					backTracker = ')';
					getFront = true;
				}	
				else if(line[front-1]=='[')
				{
					backTracker = ']';
					getFront = true;
				}
				
				if(getFront)
				{
					back = front + 1;
					while(1)
					{
						if(line[back-1]==')'| line[back-1]==']')
						{
							if(line[back-1]!=backTracker)
							{
								matching = false;
								break;
							}
							else
							{
								line[back-1]='v'; // already visited
								break;
							}
						}
						else
						{
							back++;
							if(back>len)
							{
								break;
								matching = false;
							}
						}
					}
				}

				getFront = false;

				if(!matching)
					break;
				front--;
			}
		}

		if(matching)
			cout << "Yes" << endl;
		else
			cout << "No" << endl;
		n--;
		line.clear();

	}

	return 0;
}

[brianfry713]

Don't use fflush(stdin);

[littleaich]

Thank you @brianfry713. The problem was with fflush(stdin). Now it's accepted.

[NAbdulla]

Please help
Getting WA

removed after Accepted

[arnab5574]

Why am i getting runtime error for this code?? plz help

Code: Select all

#include <iostream>
#include <stack>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
using namespace std;
int main()
{
    char a[150];
    int i,j,p,n;
    scanf("%d",&n);
    getchar();
    while(n--)
    {
        stack<char> st;
        gets(a);
        //if(a=="") {cout<<"Yes"<<endl;continue;}
        p=0,j=0;
        int count1=0,count2=0;
        for(int i=0;a[i]!='\0';i++)
        {
            if(a[i]=='[' || a[i]=='(' || a[i]=='{') {count1++;st.push(a[i]);}
            else
            {
                if(a[i]==']') if(st.top()!='[') {p=1;j=1;break;}
                else if(a[i]=='}') if(st.top()!='{') {p=1;j=1;break;}
                else if(a[i]==')') if(st.top()!='(') {p=1;j=1;break;}
                count2++;
                st.pop();
            }
        }
        //cout<<a[0]<<a[1];
        //cout<<count1<<" "<<count2;
        if(!p && !j && count1==count2) cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
        fflush(stdin);
    }
    return 0;
}

[Moaz]

Code: Select all

#include<iostream>
#include<string>
#include<stack>
using namespace std;

int main()
{
	int n;

	cin>>n;

	getchar();
	int i=0;
	while(i<n)
	{
		stack<char>st;
		string str,news;
		getline(cin,str);
		for(int j=0;j<str.length();j++)
		{
			if(str[j]==' ')
			{
				continue;
			}
			else
			{
				news+=str[j];
			}
		}
		str=news;
		for(int j=0;j<str.length();j++)
		{	
			if(str[j]=='(')
			{
				st.push('(');
			}
			else if((str[j]==')'))
			{
				if(!st.empty()&&st.top()=='(')
				{	
					st.pop();
				}
				else
				{
					st.push(str[j]); 
				}

			}
			else if(str[j]=='[')
				st.push('[');
			else if(str[j]==']')
			{
				if(!st.empty()&&st.top()=='[')
				{	
					st.pop();
				}
				else
					st.push(str[j]);
			}


		}

		if(st.empty())
			cout<<"Yes"<<endl;
		else
			cout<<"NO"<<endl;
		i++;
	}
	return 0;
}

[forhadmethun]

Code: Select all

#include <bits/stdc++.h>
using namespace std;

int main()
{
    //cout << "Hello world!" << endl;
    freopen("in.txt","r",stdin);
    int t;
    char str[130];

    cin >> t;

    getchar();
    while(t--)
    {
        stack<char> stk;

        gets(str);
        bool isTrue = true;
        if(strlen(str) %2 ==1){
            cout << "No" << endl;
            continue;
        }
        for(int i=0;str[i];i++)
        {
            if(str[i]== '('){
                stk.push(str[i]);
                continue;}
            else if(str[i] == '['){
                    stk.push(str[i]);
                continue;
            }
            if(str[i] == ']'){
                if(stk.empty()){
                    isTrue = false;
                    break;
                }
                char ch = stk.top();
                stk.pop();
                if(ch != '['){
                    isTrue = false;
                    break;
                }
            }else if(str[i] == ')'){
                if(stk.empty()){
                    isTrue = false;
                    break;
                }
                char ch = stk.top();
                stk.pop();
                if(ch != '('){
                    isTrue = false;
                    break;
                }

            }

        }

        if(isTrue == true)cout << "Yes" << endl;
        else cout << "No" << endl;

            //cout << str << endl;



    }
    return 0;
}

///why wrong answer ................??

[oja]

Input:

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1
((()

Output:

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No

Your code outputs "Yes".
After you process the whole string. Check if the stack is empty or not. If it's not empty then it's a "No".

Btw, couple of suggestions:

1-If you post your code, use the "Code" button at the top of the editor window. Your code may become more readable. Use
"Preview" button to view your post before you submit it.(Not that my posts are well-formatted).
2-Try not to mix c++ style (cin, cout, getline, etc) and c style (scanf, printf, fgets, etc) i/o in your c++ code. Choose c++ style or c style, but try not to use both. If you want speed for your c++ style i/o, you can use

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ios_base::sync_with_stdio(false);

Put it before your first use of cin or cout. And don't use "endl". You can change

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cout << "Yes" << endl;

to

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cout << "Yes\n";

endl does more work than just outputting new line. For small number of I/O, maybe there won't be any noticeable difference. But for large, your code might (or might not) finish faster.
3-You don't need to use

Code: Select all

freopen("in.txt","r",stdin);

You can just submit your code which takes input and displays output at the command line. I've tried only C++ and Java so I'm not sure if this is true with C.