C :

#include <stdio.h>
#include <string.h>
#define MAX 26


int main()
{
	char _stack[MAX];
	int top;
	char a[30];
	while (scanf("%s", &a) != EOF)
	{
		top = -1;
		for (int i = 0; i<strlen(a); i++)
		{
			//栈非空
			if (top != -1)
			{
				//出栈

				if (_stack[top] == '('&&a[i] == ')' || _stack[top] == '['&&a[i] == ']')
					top--;
				else{
					_stack[++top] = a[i];
				}
			}
			else{
				_stack[++top] = a[i];
			}
		}
		if (top == -1)
		{
			printf("Yes\n");
		}
		else
			printf("No\n");
	}

	return 0;


}

C++ :

#include <stdio.h>
#include <stack>
#include <string.h>
using namespace std;
int main()
{
	int len,i,check;
	char a[50],c;
	while(gets(a))
	{
		stack<char > que;
		que.push('b');
		check=1;
		len=strlen(a);
		for(i=0;i<len;i++)
		{
			if(a[i]=='('||a[i]=='[')
			{
			que.push(a[i]);
			continue;
		}
			else
			if(a[i]==')'||a[i]==']')
			{
				if(a[i]==')')
				{
					if(que.top()=='(')
					{
						que.pop();
						continue;
					}
					else
					{
						check=0;
						break;
					}
				}
				if(a[i]==']')
				{
					if(que.top()=='[')
					{
						que.pop();
						continue;
					}
					else
					{
						check=0;
						break;
					}
				}
			}
		}
		if(check&&que.size()==1)
		printf("Yes\n");
		else
		printf("No\n");
	}
	return 0;
}