#include <cstdio>
#include <cstdlib>
#include <vector>
#include <string>
#define NOMINMAX
#include <windows.h>

double elapsed_ms(LARGE_INTEGER start, LARGE_INTEGER end) {
    LARGE_INTEGER frequency;
    QueryPerformanceFrequency(&frequency);
    return (end.QuadPart - start.QuadPart) * 1000 / (double) frequency.QuadPart;
}

int test(char* a, char* b) {
    return *a != *b;
}

void compare_cstrings(int count, int length) {
    std::vector<char*> strings1 = std::vector<char*>(count);
    std::vector<char*> strings2 = std::vector<char*>(count);
    std::string allowed_chars = std::string("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");

    for (int str_id = 0; str_id < count; str_id++) {
        strings1[str_id] = new char[length + 1];
        strings2[str_id] = new char[length + 1];

        for (int char_id = 0; char_id < length; char_id++) {
            strings1[str_id][char_id] = allowed_chars[std::rand() % allowed_chars.length()];
            strings2[str_id][char_id] = allowed_chars[std::rand() % allowed_chars.length()];
        }

        strings1[str_id][length] = strings2[str_id][length] = '\0';
    }

    int matches = 0;
    LARGE_INTEGER start, end;
    QueryPerformanceCounter(&start);
    for (int str_id = 0; str_id < count; str_id++)
        if (test(strings1[str_id], strings2[str_id]) == 0)
            matches++;
    QueryPerformanceCounter(&end);

    for (int str_id = 0; str_id < count; str_id++) {
        delete[] strings1[str_id];
        delete[] strings2[str_id];
    }

    printf("%d strings\t%d chars\t%fms\t(%d matches)\n", count, length, elapsed_ms(start, end), matches);
}

int main(int argc, char** argv) {
    srand(0);
    for (int length = 1; length <= 250; length++)
        compare_cstrings(250*1000, length);
}