mike mike - 8 days ago 6
C++ Question

Break if statement c++ error

I'm writing linear and quadratic probing hash table program.

This is a for-loop I used for linear probing function and it works perfectly fine.

//when there's a collision increase i by 1 until finding empty slot
for(i = (hashVal % tableSize+1) % tableSize; i <tableSize; i++)
if(a[i] == -1){
a[i] = hashVal;
break;
}


so I wrote a for loop again in quadratic probing function to deal with collision

//when there's a collision increase i by i^2
j = 0;

for(i=((hashVal % tableSize+1) % tableSize); i < tableSize; i++)
j = i^2;
if(a[j] == -1){
a[j] = hashVal;
break;
}


But when I compile quadratic probing, I'm getting this error

error: 'break' statement not in loop or switch statement


I am really confused why it causes error in the second one while it is fine in linear probing. Could anyone explain why?

Answer
for(i=((hashVal % tableSize+1) % tableSize); i < tableSize; i++)
    j = i^2;

this is your cycle, since you didn't put curly braces around it.

fix is simple, put those braces:

for(i=((hashVal % tableSize+1) % tableSize); i < tableSize; i++)
{
    j = i^2;
    if(a[j] == -1){
        a[j] = hashVal;
        break;
    }
}

Rule of thumb - always put curly braces when you use cycle or if-statement, because it helps you to not make such errors as this.