Vector element comparison help

[marmacc]

I'm trying to compare values from two different vectors--if they are the same, a number is incremented, to count the similarities.
There's a four-element int vector with random user input (e.g. 8 9 0 7)
and a ten-element int vector containing 0-9 (i.e. 0 1 2 3 4 5 6 7 8 9).

I tried comparing them with something like this:
vector<int>input;
vector<int>integers;
int total_hits = 0;

for (int i=0; i < 4; ++i){
for (int j=0; j < 10; ++j)
if (input[i] == integers[j])
++total_hits;

I get the error: pointer to a function used in arithmetic (in regards to input[i] == integers[j]), and another saying that C++ forbids comparison between pointer and integer (regarding the same line).
Is there any way to compare two vector elements??????

[kbw]

A container knows it's size. So your code should look like:

for (size_t i = 0; i != input.size(); ++i)
    for (size_t j = 0; j != integers.size(); ++j)
        if (input[i] == integers[j])
            ++totoal_hits;

[marmacc]

But the problem is that the compiler won't allow me to do
if (input[i] == integers[j]), saying that I'm using a pointer to a function in arithmetic and that I can't compare a pointer and an integer. I think it's saying that input[i] is a pointer to a function and integers[j] is an integer, even though both should be integers.

[kbw]

That doesn't make sense from what you've posted.

I can only suggest that you post all your relevant code.

[marmacc]

This is the code I have:

vector<int> input();
vector<int> integers(range_top);
int zero = 0;
int total_hits = 0;

for (int i=0; i < range_top; ++i){ // put values into integer vector
integers.push_back(i);
}
for (int i=0; i < num_slots; ++i){ // count similarities in vectors
for (int j=0; j < range_top; ++j)
if (input[i] == integers[j])
++total_hits
}

And these are the errors I get:

proj3.cc:210:19: warning: pointer to a function used in arithmetic [-Wpointer-arith]
if (input[i] == integers[j])
^
proj3.cc:210:34: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
if (input[i] == integers[j])
^

[kbw]

You're still not using .size().

[JLBorges]

> vector<int> input();

That is the declaration of a function.

This is the definition of an empty vector<>: vector<int> input ;