Can someone explain why is this code failing. It passes 24 test cases only

class Solver{
    public:
        string main_result;
        bool completed = false;
        void compute(vector<int>arr,int sum,string result){
            int cp_sum = sum;
            if(sum==0){
                int n = arr.at(0);
                arr.erase(arr.begin());
                compute(arr,n,result+to_string(n));
                return;
            }
            if(arr.size() == 0){
                if(sum%101==0){
                    main_result = result;
                    completed = true;
                   // cout<<main_result.length()<<endl;
                    cout<<sum<<endl;
                    return;
                }
                return;
            }
            for(int i = 1;i<=3 && completed == false;i++){
                int n = arr.at(0);
                if(i == 1){
                    //sum+=n;
                    arr.erase(arr.begin());
                    compute(arr,sum+n,result+ "+" + to_string(n));
                }
                if(i == 2){
                    //sum-= n;
                    arr.erase(arr.begin());
                    compute(arr,sum-n,result+ "-" + to_string(n));
                }
                if(i == 3){
                    //sum*=n;
                    arr.erase(arr.begin());
                    compute(arr,sum*n,result+ "*" + to_string(n));
                }
                arr.insert(arr.begin(),n);
               // sum = cp_sum;
                
            }
            
        }
};
string arithmeticExpressions(vector<int> arr) {
    Solver obj;
    obj.compute(arr, 0, "");
    string ans = obj.main_result;
		
    
    return ans;
}

Simplest Solution I have Seen So far:-

Code

class Result {

public static String ans="";

public static boolean Solve(List<Integer>arr,int prev,String cur,int idx,boolean map[]  []){
        prev=prev%101;

 if(idx==arr.size()){
        if(prev%101==0){
                 ans=cur;
                    return true;  
             }
return false;
}

 //Checking if at this index Previsiously we Got this remainder(prev)

if(map[idx][prev+101])return false;
map[idx][prev+101]=true;

    //recursion   

    if(Solve(arr,prev+arr.get(idx)%101,cur+"+"+arr.get(idx),idx+1,map))return true;
    if(Solve(arr,prev-arr.get(idx)%101,cur+"-"+arr.get(idx),idx+1,map))return true;
    if(Solve(arr,prev*arr.get(idx)%101,cur+"*"+arr.get(idx),idx+1,map))return true;

   return false;
}

public static String arithmeticExpressions(List<Integer> arr){

boolean[][]map=new boolean[arr.size()][2*101];

Solve(arr,arr.get(0),""+arr.get(0),1,map);

 return ans;
}

}

Despite this problem being in the category "Recursion", I feel it much more appropriate to use DP.

Here what that looks like in Python3:

def arithmeticExpressions(arr):
    this = [None] * 101
    this[arr[0]] = [arr[0]]
    for a in arr[1:]:
        if this[0]:
            this[0] += ['*', a]
        else:
            that = [None] * 101
            for i, v in enumerate(this):
                if v is not None:
                    that[(i+a)%101] = this[i] + ['+', a]
                    that[(i-a)%101] = this[i] + ['-', a]
                    that[(i*a)%101] = this[i] + ['*', a]
            this = that
    return ''.join(map(str, this[0]))

Here is Arithmetic Expressions problem solution in Python Java C++ and C programming - https://programs.programmingoneonone.com/2021/07/hackerrank-arithmetic-expressions-problem-solution.html

Hi, Can someone tell what is the issue with this code.I get RunTimeError for 7th test case . Its not TLE Error

def getexpression(arr,operators,curInd,curresult,expr):

if curInd == len(arr):
         if curresult%101 ==0:
             return([True,expr])
         else:
             return([False,""])

resultTillnow=curresult

expTillnow=expr

  for op in operators:
    val2=arr[curInd]
    if op=="ADD":
        result=resultTillnow+val2
        oper="+"
    elif op=="MUL":
        result=resultTillnow*val2
        oper="*"
    else:
        result=resultTillnow-val2
        oper="-"
    nexpr=expTillnow+oper+str(val2)    
    stat,e=getexpression(arr,operators,curInd+1,result,nexpr)
    if stat:
        return([stat,e])
return([False,""])                            

def arithmeticExpressions(arr):

operators=['ADD','MUL','SUB']

stat,expr = getexpression(arr,operators,1,arr[0],str(arr[0]))  

    if stat:

    return expr
    tat:
    return(expr)
   return exprelse:
    return("")