algorithm/Java
1
0
Fork 0
mirror of https://github.com/TheAlgorithms/Java.git synced 2025-07-06 17:29:31 +08:00
Code Issues Packages Projects Releases Wiki Activity

refactor: BoardPath (#5431)

Browse Source 
refactor: BoardPath

Co-authored-by: alxkm <alx@alx.com>
This commit is contained in:
Alex Klymenko
2024-08-30 10:12:31 +02:00
committed by GitHub
parent c5b72816f3
commit f8ff6af893
2 changed files with 58 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
src/main/java/com/thealgorithms/dynamicprogramming/BoardPath.java
View File

@ -1,46 +1,16 @@
package com.thealgorithms.dynamicprogramming;
/*
* this is an important Algo in which
* we have starting and ending of board and we have to reach
* we have to count no. of ways
* that help to reach end point i.e number by rolling dice
* which have 1 to 6 digits
Test Case:
here target is 10
int n=10;
startAlgo();
System.out.println(bpR(0,n));
System.out.println(endAlgo()+"ms");
int[] strg=new int [n+1];
startAlgo();
System.out.println(bpRS(0,n,strg));
System.out.println(endAlgo()+"ms");
startAlgo();
System.out.println(bpIS(0,n,strg));
System.out.println(endAlgo()+"ms");
*/
public final class BoardPath {
private BoardPath() {
}
public static long startTime;
public static long endTime;
public static void startAlgo() {
startTime = System.currentTimeMillis();
}
public static long endAlgo() {
endTime = System.currentTimeMillis();
return endTime - startTime;
}
/**
* Recursive solution without memoization
*
* @param start - the current position
* @param end - the target position
* @return the number of ways to reach the end from the start
*/
public static int bpR(int start, int end) {
if (start == end) {
return 1;
@ -54,6 +24,14 @@ public final class BoardPath {
return count;
}
/**
* Recursive solution with memoization
*
* @param curr - the current position
* @param end - the target position
* @param strg - memoization array
* @return the number of ways to reach the end from the start
*/
public static int bpRS(int curr, int end, int[] strg) {
if (curr == end) {
return 1;
@ -71,15 +49,23 @@ public final class BoardPath {
return count;
}
/**
* Iterative solution with tabulation
*
* @param curr - the current position (always starts from 0)
* @param end - the target position
* @param strg - memoization array
* @return the number of ways to reach the end from the start
*/
public static int bpIS(int curr, int end, int[] strg) {
strg[end] = 1;
for (int i = end - 1; i >= 0; i--) {
int count = 0;
for (int dice = 1; dice <= 6 && dice + i < strg.length; dice++) {
for (int dice = 1; dice <= 6 && dice + i <= end; dice++) {
count += strg[i + dice];
}
strg[i] = count;
}
return strg[0];
return strg[curr];
}
}