Help with array function please! Not sure why it won't work

[qwerty2222]

I am supposed to make a function that can do the following:

function: bool subsequence(const string a1[], int n1, const string a2[], int n2)

Task:
If all n2 elements of a2 appear in a1, in the same order (though not necessarily consecutively), then return true. Return false if a1 does not contain a2 as a subsequence. (Of course, the empty sequence is a subsequence of any sequence.) Return false if this function is passed any bad arguments.

Here is what I tried and I have no idea why it won't work. Any help is appreciated!

code:

#include <iostream>
#include <string>


using namespace std;

bool subsequence(const string a1[], int n1, const string a2[], int n2)
{
	if (n1 < 0 || n2 < 0 || n2 > n1) { 
	return false;
}

	else if (n2 == 0) {
	return true;
}


for (int i = 0; i < n1; i++) { 
	if (a1[i] == a2[0]) 
	{
		int j = 0;
			for (int k = 0; k + i < n1; k++)
			{
				if (a1[i + k] == a2[j])
				{
					j++; 
					if (j = n2) 
						return true;
				}
			}
		}
}
return false;
}

It runs fine it just gives true on many cases when it should give false.




edit: fixed formatting

[MrHutch]

Please use code tags and indentation when you post code - it makes it a lot easier to read.

What are the test cases?

Something definitely looks off with the last if statement, which is assigning, not comparing.

[qwerty2222]

Sorry about the formatting. Wasn't sure how to work it.

A test case it fails on is
string h[7] = {"1" , "2", "3", "4", "5", "6", "7"}
string g[4] = {"1", "2", "cat", "6"}
bool subsequence(h, 7, g, 4)

[keskiverto]

Use of code tags, see http://www.cplusplus.com/articles/jEywvCM9/

The std::includes does similar (but not exactly same) operation. See http://www.cplusplus.com/reference/algorithm/includes/