In [7]:

    

import operator;

nGlobalList = list(range(1,7));
print(nGlobalList)
opStrings = ["+","-","/","*"]

def minus(a,b):
    return a-b;

ops = [operator.add, minus,operator.truediv,operator.mul]
nOPs = len(ops)


    

    




[1, 2, 3, 4, 5, 6]

In [ ]:

    

stringList = [str(i) for i in nGlobalList];
resList = [];
computeBinaryOperator(nGlobalList,stringList,"",resList)
print(len(resList))


    

In [6]:

    

nCombs = 0;
def computeBinaryOperator(nList,nStringList, depthString, resList ):
        depthString+=" "
        
        listSize = len(nList);
        if(listSize == 1):
            print(nStringList[0], "result: ",nList[0])
            resList.append((nStringList[0],nList[0]));
        
        #print(depthString,nStringList,nList)
        for i in range(0,listSize):
            #choose first number in 1:listSize-1
            x = nList[i];
            xStr = nStringList[i];
            
            for j in range(1,listSize):
                #choose second number
                k = (j+i)%listSize;
                y = nList[k];
                yStr = nStringList[k];
                
                # apply operator
                for oIdx in range(0,nOPs):
                    try:
                        res = ops[oIdx](x,y); # result is always at beginning of the new list
                    except:
                        res = float("Inf");
                        
                    resString = "(" + xStr + opStrings[oIdx] + yStr +")";
                    
                    # call recursion with new list (otherwise call by reference,notg good
                    nListNew = nList.copy();
                    nStringListNew = nStringList.copy();
                    
                    #Overwrite choosen x
                    nListNew[i] = res; # put result at position i
                    nStringListNew[i] = resString;
                    # remove choosen element y
                    nListNew.pop(k); nStringListNew.pop(k);  
                    computeBinaryOperator(nListNew,nStringListNew,depthString,resList);


    

In [4]:

    

nCombs = 0;
def computeBinaryOperator2(nList,resList):
        listSize = len(nList);
        if(listSize == 1):
            resList.append(nList[0]);
        
        #print(depthString,nStringList,nList)
        for i in range(0,listSize):
            #choose first number in 1:listSize-1
            x = nList[i];
            
            for j in range(1,listSize):
                #choose second number
                k = (j+i)%listSize;
                y = nList[k];
                
                # apply operator
                for oIdx in range(0,nOPs):
                    try:
                        res = ops[oIdx](x,y); # result is always at beginning of the new list
                    except:
                        res = float("Inf");
  
                    # call recursion with new list (otherwise call by reference,notg good
                    nListNew = nList.copy();
                    #Overwrite choosen x
                    nListNew[i] = res; # put result at position i
                    # remove choosen element y
                    nListNew.pop(k); 
                    computeBinaryOperator2(nListNew,resList);


    

In [6]:

    

resList = [];
computeBinaryOperator2(nGlobalList,resList)
print(len(resList))


    

    




737280

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