673 - Parentheses Balance

[SilVer DirectXer]

o, i change my coding to a Full C program , not using classes and using scanf and printf instead of using cin cout, and finally i got a AC!

really thanks.

[zzylhy]

#include<iostream.h>
#include<stdio.h>

int main()
{
int n,i;
char s[130],ch,flag;
cin>>n;
while(n>0)
{
n--;
i=0;
flag=1;
while(1)
{
ch=getchar();
if(ch==10)
break;
else
if((ch=='(')||(ch=='['))
{
i++;
s=ch;
}
else
{
if(i==0)
{
i=1;
ch=getchar();
if(ch==10)
break;
}

if(((ch==']')&&s=='[')||((ch==')')&&(s=='(')))
{
i--;

}
else
{
i=1;
}

}
}
if(i==0)
cout<<"Yes"<<endl;
else
cout<<"No"<<endl;
}
return 0;
}

Help,why always WA?

[udvat]

plz check my code n let me know whats the fault?



[cpp]
#include<stdlib.h>
#include<string.h>
#include<stdio.h>

void main()
{

char C;
char arr[200]={0};
char x[200]={0};
int N;
int i,y,l;

scanf("%d",&N);
getchar();

y=0;

while(N--)
{

y=0;


gets(x);


l=strlen(x);

if(l==0)
{printf("Yes\n");
continue;}


if(l%2)
{printf("No\n");
continue;}


for(i=0;i<=l;i++)
{


C=x;


if(C=='\0')
{
if(!strcmp(arr,NULL))
{
printf("Yes\n");
}

else
{
printf("No\n");

}
break;
}




if(C=='(' || C=='[')
{
arr[y++]=C;
arr[y]='\0';
}

else if(C==')')
{
if(y==0)
{
arr[y++]=C;
arr[y]='\0';
}

else
{
if(arr[--y]!='(')
{
arr[y++]=C;
arr[y]='\0';
}

else
arr[y]='\0';

}


}


else if (C==']')
{
if(y==0)
{
arr[y++]=C;
arr[y]='\0';
}

else
{
if(arr[--y]!='[')
{
arr[y++]=C;
arr[y]='\0';
}

else
arr[y]='\0';


}

}




}

}




}



[/cpp]

[UFP2161]

[cpp]
if(!strcmp(arr,NULL))
[/cpp]

I'm pretty certain you can't pass NULL to strcmp. If you want the empty string, use "" instead.

[udvat]

I got accepted!!!!!!!I really dnt know strcmp cant work with NULL.thanks again

[UFP2161]

Like all functions in <string.h>, it requires that the character array ends in '\0'. However, if you pass NULL as a pointer to any of those functions, the function will attempt to dereference it first so it can check for '\0' and thus the end of the string, but since you passed NULL, it can't dereference NULL, thus, segmentation fault.

[Sarmento]

It seems to be working just fine... till the moment I submit it... Can anyone give me a clue why?

Code: Select all

[c]
include <stdio.h>
#include <string.h>

int n, i,j, length;
char str[130];


void rem_chars(int a){
	int x;
	char ret[length];
	for (x = 0; x < length; x++){
		if (x < a){
			ret[x] = str[x];
		}
		else if (x > a+1){
			ret[x-2] = str[x];
		}
	}
	ret[x-2]='\0';
	strcpy(str,ret);
	length = strlen(str);
}

int main(){
	scanf("%d",&n);
	for(i = 0; i < n; i++){
		scanf("%s", str);
		length = strlen(str);
		for (j = 0; j <= length; j++){
			if (length == 0){
				printf("Yes\n");
				break;
			}
			else{
				if ((str[j] == ')' && str[j-1] == '(') || (str[j] == ']' && str[j-1] == '[')){
					rem_chars(j-1);
					j = -1;
				}
				else if((str[j] == ')' && str[j-1] != '(') || (str[j] == ']' && str[j-1] != '[') || (j == length && length > 0)){
					printf("No\n");
					break;
				}
			}
		}
	}
	return 0;	
}
[/c]

[Dmytro Chernysh]

Well, your code is not that clear... Try to think (and implement a stack...
I can give you my AC program, if you really got stuck.

[Joe]

why do I get Runtime error in problem 673? Please help.
[cpp]#include <stdio.h>
#include <iostream.h>
#include <stdlib.h>
#include <string.h>
char b[129];

void init(){
for(int i=0;i<129;i++)
b='\0';
}
class stack{

public:
int index;
stack(){index=0;}
int data[129];
void push(int n){data[index++]=n;}
int pop(){return(index==0)?-5:data[--index];}
};

int main()
{
stack s;
bool flag;
int res;
int c,i=0;
init();
scanf("%d\n",c);
for (int k=0;k<c;k++){
init();
i=0;
scanf("%s",b);
flag=true;
while(i<strlen(b)){
switch (b){
case '(': s.push(0);
break;
case '[': s.push(1);
break;
case ')':{
res=s.pop();
if (res!=0) flag=false;
}
break;
case ']':{
res=s.pop();
if (res!=1) flag=false;
}
break;
}
i++;
}
if (!flag || s.index!=0 || b!='\0') cout<<"No\n";
else cout<<"Yes\n";
}
return 0;
}[/cpp]
thnx

[Sajid]

umm, check with few large array size, like 130 or 132.

[AaronWu]

I have tried many inputs as are mentioned in the former topics but I still have no idea about WA with my code. Could anybody spare some time checking with my code and tell me the matter with my code? Thank you in advance.

[cpp]
#include <iostream.h>
#include <stdio.h>
int solve(char *);
int main()
{
long int n,count ;
int result;
char *chs = new char[129];
cin>>n;
for(count=0;count<n;count++)
{
gets(chs);
result = solve(chs);
if(result==1)
cout<<"Yes"<<endl;
else cout<<"No"<<endl;
}
return 0;
}
..........

}[/cpp]

[turuthok]

The problem is when you read the first line (n) ... using cin >> n, I guess it won't advance to the next line or something like that ... causing problems on the next cases ... try to use gets(), followed by atoi() to obtain n ... you should get AC after that.

-turuthok-

[AaronWu]

I guess it won't advance to the next line or something like that

-turuthok-

I have succeeded solving other problems in the same way before.and they goes so well on the online judge as they work in my computer.So,do you mean that my codes are all right except for the above?
Looking forward to reply~

[AaronWu]

I guess it won't advance to the next line or something like that

-turuthok-

I have succeeded solving other problems in the same way before.and they goes so well on the online judge as they work in my computer.So,do you mean that my codes are all right except for the above?
Looking forward to reply~

[AaronWu]

I guess it won't advance to the next line or something like that

-turuthok-

I have succeeded solving other problems in the same way before.and they goes so well on the online judge as they work in my computer.So,do you mean that my codes are all right except for the above?
Looking forward to reply~