#include <algorithm>

#include <functional>

using namespace std;

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

int    compareC (const char* c1, const char* c2){  return (*c1 < *c2)? 1: (*c1 > *c2) ? -1 : 0; }

int    compareS (const char& c1, const char& c2) { return (c1 < c2); }

template<class T>

struct compareF { int operator()(const T& c1, const T& c2) { return (c1 > c2); } };

int main()

{

{

char msg[] = "Hello world";

printf("\nC-sorting: Qsort-------------------------------------------------------\n");

qsort(&msg[0], strlen(msg), sizeof(char), (int (*)(const void *, const void *))compareC);

printf("%s\n", msg);

}

{

char msg[] = "welcome to todayhumor";

printf("\nstd-sorting with function ---------------------------------------------\n");

char* bgn = &msg[0];

char* end = &msg[strlen(msg)];

std::sort(bgn, end, compareS);

printf("%s\n", msg);

}

{

char msg[] = "c++ functor is difficult but very cool.";

printf("\nstd-sorting with functor ---------------------------------------------\n");

char* bgn = &msg[0];

char* end = &msg[strlen(msg)];

std::sort(bgn, end, compareF<int>());

printf("%s\n", msg);

}

{

char msg[] = "c++ goes to complete the abstraction of language as having a lambda expression.";

printf("\nstd-sorting with lambda ---------------------------------------------\n");

char* bgn = &msg[0];

char* end = &msg[strlen(msg)];

std::sort(bgn, end, [](const char& c1, const char& c2)->int{ return (c1 < c2); });

printf("%s\n", msg);

}

return 0;

}