## C++, other, tower_of_hanoi.cpp

``````/**
* @file
* @brief Solve the [Tower of
* Hanoi](https://en.wikipedia.org/wiki/Tower_of_Hanoi) problem.
*/
#include <iostream>

/**
* Define the state of tower
*/
struct tower {
//! Values in the tower
int values[10];
//! top tower ID
int top;
};

/** Display the towers */
void show(const struct tower *const F, const struct tower *const T,
const struct tower *const U) {
std::cout << "\n\n\tF : ";
for (int i = 0; i < F->top; i++) {
std::cout << F->values[i] << "\t";
}
std::cout << "\n\tU : ";
for (int i = 0; i < U->top; i++) {
std::cout << U->values[i] << "\t";
}
std::cout << "\n\tT : ";
for (int i = 0; i < T->top; i++) {
std::cout << T->values[i] << "\t";
}
}

/** Move one disc from one tower to another
* \param [in,out] From tower to move disk *from*
* \param [in,out] To  tower to move disk *to*
*/
void mov(tower *From, tower *To) {
--From->top;
To->values[To->top] = From->values[From->top];
++To->top;
}

/**
* Recursive algorithm to solve the puzzle
* \param [in] n starting number of disks
* \param [in,out] From  tower to move disks from
* \param [in,out] Using temporary tower for the puzzle
* \param [in,out] To  tower to move disk to
*/
void TH(int n, tower *From, tower *Using, tower *To) {
if (n == 1) {
mov(From, To);
show(From, To, Using);
} else {
TH(n - 1, From, To, Using);
mov(From, To);
show(From, To, Using);
TH(n - 1, Using, From, To);
}
}

/** Main function */
int main() {
struct tower F, U, T;

F.top = 0;
U.top = 0;
T.top = 0;

int no;

std::cout << "\nEnter number of discs : ";
std::cin >> no;

for (int i = no; i > 0; i--) {
F.values[F.top++] = i;
}

show(&F, &T, &U);
TH(no, &F, &U, &T);

return 0;
}
``````