C :

#include<string.h>
void Output( char [] ) ;
int Solve( char [] , int ) ;  
int pd( char [] ,  int , int );
int main(void)
{
	char zf[256]; 
	gets( zf );
	Solve( zf , 0  ); 
	Output( zf ) ;  
	return 0 ; 
}
int pd( char zf[] , int left, int right )
{
	int i , leftAcount ;
    if( zf[ left - 1 ] == '-')
	{    
 
        i = left;
        leftAcount = 1;
        while( ++ i < right)
		{
            if(zf[i] == '(') 
			{
				leftAcount ++;
			}
            if(zf[i] == '+' && leftAcount == 1) 
			{
				return 0;
		    } 
        }
    }
    if( zf[ left - 1 ] == '/')
	{
		return 0;    	
	} 
    if(zf[ left - 1 ] != '*' && zf[ left - 1 ] != '/' && zf[ right + 1 ] != '*' && zf[ right + 1 ] != '/')
	{
	   return 1;
	} 
 
 
    i = left ;
    leftAcount = 1;
    while(++i < right)
	{
        if(zf[i] == '(') 
		{
			leftAcount ++;
		}
        if(zf[i] == '*' && leftAcount == 1)
		{
			return 1;	
		}  
    }
 
 
    return 0;
}
int Solve( char zf[]  , int i  ) 
{
	int left , right ; 
	while( zf[i] != '\0')
	{
		if( zf[i] == ')')
		{
			return i ; 
		}
		if( zf[i] == '(')
		{
			left = i ; 
			right = Solve( zf , i + 1  ) ;
			i = right ;  
			if( pd( zf , left , right ))
			{
				zf[left] = ' ' ;
				zf[right] = ' ' ;  
			}
		}
		i ++ ; 	
	} 
}
void Output( char zf[] ) 
{
	int i = 0 ;   
	while( zf[ i ] != '\0')
	{
		
        if(zf[i] != ' ')
		{
            putchar(zf[i]);
        }
        i ++ ; 
    }
}

C++ :

#include "iostream"
#include "string"
#include "stdio.h"
#include "ctype.h"
#include "algorithm"
#include "stack"
using namespace std;

int cacluExprePriority(string str,bool &hasC)
{
    int left=0;
    int right=0;
    bool bfind=false;
    for(int i=0;i<str.size();i++)
    {
        if(str[i]=='(')
            left++;
        if(str[i]==')')
            right++;
        if(str[i]=='/')
            hasC=true;
        if(str[i]=='*'||str[i]=='/')
        {
            if(left==right)
                return 2;
        }
        if(str[i]=='+'||str[i]=='-')
        {
            bfind=true;
        }
    }
    return bfind?1:-1;
}
bool vis[1000];
int safe(int i,int n)
{
    if(i<0)
        return 0;
    if(i>=n)
        return n-1;
    return i;
}
void findIndexOfBrackets(string str)
{
    stack<int>q;
    for(int i=0;i<str.size();i++)
    {
        if(str[i]=='(')
        {
            q.push(i);
        }
       if(str[i]==')')
        {
            int s=q.top();
            int t=i;
            bool hasC=false;
             int priority=cacluExprePriority(str.substr(s+1,t-s-1),hasC);
             q.pop();
             bool temp=false;
             if(s-1>=0&&cacluExprePriority(str.substr(safe(s-1,str.size()),1),temp)>=cacluExprePriority(str.substr(safe(t+1,str.size()),1),temp))
             {
                 char op=str[s-1];
                 {
                 if(op=='+')
                 {
                    vis[s]=vis[t]=true;
                 }
                if(op=='-')
                {
                    if(priority==2)
                        vis[s]=vis[t]=true;
                }
                if(op=='*')
                {
                    if(priority==2&&hasC==false)
                        vis[s]=vis[t]=true;
                }
              }
             }
             else  if(t+1<str.size())

            {


                    char op=str[t+1];
                    if(op=='+'||op=='-')
                    {
                        vis[s]=vis[t]=true;
                    }

                    if(op=='*'||op=='/')
                    {
                        if(priority==2)
                            vis[s]=vis[t]=true;
                    }
            }
        }
    }

}
int main()
{
    string exper;
    cin>>exper;

    findIndexOfBrackets(exper);
    for(int i=0;i<exper.size();i++)
        if(vis[i]==false)
            cout<<exper[i];
    cout<<endl;

    return 0;
}

Java :

import java.util.Arrays;
import java.util.Scanner;

public class Main {
		public static void main(String[] args) {
			Scanner sca=new Scanner(System.in);
			String s=sca.next();
			String str="";
			int[] a=new int[s.length()];
			for(int i=0;i<s.length();i++) {
				char c=s.charAt(i);
				if(a[i]==1) {
					continue;
				}
				if(c=='(') {
					boolean bo=true;
					if(i-1>=0) {
						if(s.charAt(i-1)=='*' || s.charAt(i-1)=='/' ) {  //判断左括号前是否有乘除
							bo=false;
						}
					}
					if(!bo) {
						continue;
					}
					int index=i+1;
					int zuo=0;
					boolean jian=true;
					if(i-1>=0) {
						if(s.charAt(i-1)=='-') {  
							jian=false;
						}
					}
					while(true) {    //找到匹配的右括号
						if(!jian && s.charAt(index)=='+') {  //判断左括号是-时，括号里有没有+
							bo=false;
							break;
						}
						if(s.charAt(index)==')' && zuo==0) {
							break;
						}
						if(s.charAt(index)=='(') {
							zuo++;
						}
						if(s.charAt(index)==')') {
							zuo--;
						}
						index++;
					}
					if(!bo) {
						continue;
					}
					boolean bo2=true;
					if(index+1<s.length()) {
						if(s.charAt(index+1)=='*' || s.charAt(index+1)=='/') {  //判断右括号右边是否有乘除
							bo2=false;
						}
					}
					if(bo2) {   //记录可以删除的括号位置
						a[i]=1;
						a[index]=1;
					}
				}
			}
			for(int i=0;i<s.length();i++) {
				if(a[i]==0) {
					str+=s.charAt(i);
				}
			}
			System.out.println(str);
		}
	}