Generate ladder of integers using the least number of unique characters (in C++)
I believe I managed to remove the = character from your code, although it now is significantly slower

#include&lt;iostream&gt;

int i;
int ii;
int iii;
int iiii;

int main() {
    std::cin &gt;&gt; i;
    i++;
    for(ii++; ii &lt; i;) {
    for(;iii&gt;iiii;iii++);
    for(;iii&lt;iiii;iii++);
    ii++;
        for(iii++; iii &lt; ii; iii++) {
            std::cout &lt;&lt; iii &lt;&lt; " ";
        }
        std::cout &lt;&lt; std::endl;
    }
}


Its not pretty, but by abusing integer overflow we can get back to 0 without using =

Also we had to change the guards a little. Unfortunately because of the include I couldn't get rid of all new line characters (although its close) so that may be the next avenue for investigation. 

Edit: Run out of time for now, but if you include and use strstream and various other libraries, I think you may be able to remove the " character too, again using integers to arrive at the correct character for space and passing it into the strstream