56 lines
1.5 KiB
Rust
56 lines
1.5 KiB
Rust
/*
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* File: hanota.rs
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* Created Time: 2023-07-15
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* Author: codingonion (coderonion@gmail.com)
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*/
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#![allow(non_snake_case)]
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/* Move a disc */
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fn move_pan(src: &mut Vec<i32>, tar: &mut Vec<i32>) {
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// Take out a disc from the top of src
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let pan = src.remove(src.len() - 1);
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// Place the disc on top of tar
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tar.push(pan);
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}
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/* Solve the Tower of Hanoi problem f(i) */
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fn dfs(i: i32, src: &mut Vec<i32>, buf: &mut Vec<i32>, tar: &mut Vec<i32>) {
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// If only one disc remains on src, move it to tar
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if i == 1 {
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move_pan(src, tar);
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return;
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}
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// Subproblem f(i-1): move the top i-1 discs from src with the help of tar to buf
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dfs(i - 1, src, tar, buf);
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// Subproblem f(1): move the remaining one disc from src to tar
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move_pan(src, tar);
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// Subproblem f(i-1): move the top i-1 discs from buf with the help of src to tar
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dfs(i - 1, buf, src, tar);
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}
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/* Solve the Tower of Hanoi problem */
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fn solve_hanota(A: &mut Vec<i32>, B: &mut Vec<i32>, C: &mut Vec<i32>) {
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let n = A.len() as i32;
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// Move the top n discs from A with the help of B to C
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dfs(n, A, B, C);
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}
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/* Driver Code */
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pub fn main() {
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let mut A = vec![5, 4, 3, 2, 1];
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let mut B = Vec::new();
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let mut C = Vec::new();
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println!("Initial state:");
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println!("A = {:?}", A);
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println!("B = {:?}", B);
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println!("C = {:?}", C);
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solve_hanota(&mut A, &mut B, &mut C);
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println!("After the discs are moved:");
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println!("A = {:?}", A);
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println!("B = {:?}", B);
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println!("C = {:?}", C);
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}
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