The -m32 is telling gcc to compile for a 32-bit platform. On a 64-bit platform, gcc normally only comes with 64-bit libraries. You have two options:

1. Install 32-bit headers and libraries. Here's how you'd do this on Ubuntu.

   Run this command:

   sudo apt-get install gcc-multilib
   

2. Compile for 64-bit instead. Modify this line in the file named configure:

    CFLAGS="-m32 -ansi -D_SVID_SOURCE -DOSS_AUDIO -D'ARCH=\"$host_cpu\"' $CFLAGS"
   

   Delete -m32, giving you:

    CFLAGS="-ansi -D_SVID_SOURCE -DOSS_AUDIO -D'ARCH=\"$host_cpu\"' $CFLAGS"
   

   Run ./configure, then make clean, then make

   However, I would recommend against this approach. The library authors went out of their way to make this build for 32 bits on a 64 bit system, and I can't guarantee that it will work correctly if you do this. (It does compile, though.)

According to an answer to a similar question on stackexchange linking to the debian wiki the x86-64-linux-gnu folder is for the linux multiarch implementation, ie supporting cross-architecture dependencies.

from debian wiki: "Multiarch is the term being used to refer to the capability of a system to install and run applications of multiple different binary targets on the same system"

There's a more detailed explanation here, from this stackoverflow post.

EDIT: here's an ubuntu wiki post about it, probably more relevant here

It does look like a cross-platform compilation issue. Did you install the multilib packages:

sudo apt install gcc-multilib g++-multilib

If you've installed a version of gcc / g++ that doesn't ship by default you'll want to match the version as well:

sudo apt-get install gcc-4.8-multilib g++-4.8-multilib

Related question.

You misspelled the header: #include <bits/stdc++h.> when it should be #include <bits/stdc++.h>

Also its not a standard header, its a GCC header. So it will only work with that compiler and not for example, Visual Studio.

Youre better off using the standard headers instead of relying on bits/stdc++ to include them all. Because it can eventually drop some and suddenly your code wont work, and since it includes all these headers, your compile times will be a lot slower.

In your case, the header you need is #include <iostream>

Adding this answer partially because it fixed my problem of the same issue and so I can bookmark this question myself.

I was able to fix it by doing the following:

sudo apt-get install gcc-multilib g++-multilib

If you've installed a version of gcc / g++ that doesn't ship by default (such as g++-4.8 on lucid) you'll want to match the version as well:

sudo apt-get install gcc-4.8-multilib g++-4.8-multilib