Minimum number of Fibonacci jumps to reach end (original) (raw)
Last Updated : 12 Jul, 2025
Given an array of 0s and 1s, If any particular index i has value 1 then it is a safe index and if the value is 0 then it is an unsafe index. A man is standing at index -1(source) can only land on a safe index and he has to reach the Nth index (last position). At each jump, the man can only travel a distance equal to any Fibonacci Number. You have to minimize the number of steps, provided man can jump only in forward direction.
Note: First few Fibonacci numbers are - 0, 1, 1, 2, 3, 5, 8, 13, 21....
Examples:
Input: arr[]= {0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0}
Output: 3
The person will jump from:
- index -1 to index 4 (a distance of jump = 5)
- index 4 to index 6 (a distance of jump = 2)
- index 6 to the destination (a distance of jump = 5)
Input: arr[]= {0, 0}
Output: 1
The person will jump from:- index -1 to destination (a distance of jump = 3)
Approach:
- First, we will create an array fib[] for storing fibonacci numbers.
- Then, we will create a DP array and initialize it with INT_MAX and the 0th index DP[0] = 0 and will move in the same way as Coin Change Problem with minimum number of coins.
- The DP definition and recurrence is as followed:
DP[i] = min( DP[i], 1 + DP[i-fib[j]] )
where i is the current index and j denotes
the jth fibonacci number of which the
jump is possible
- Here DP[i] denotes the minimum steps required to reach index i considering all Fibonacci numbers.
Below is the implementation of the approach:
C++ // A Dynamic Programming based // C++ program to find minimum // number of jumps to reach // Destination #include <bits/stdc++.h> using namespace std; #define MAX 1e9 // Function that returns the min // number of jump to reach the // destination int minJumps(int arr[], int N) { // We consider only those Fibonacci // numbers which are less than n, // where we can consider fib[30] // to be the upper bound as this // will cross 10^5 int fib[30]; fib[0] = 0; fib[1] = 1; for (int i = 2; i < 30; i++) fib[i] = fib[i - 1] + fib[i - 2]; // DP[i] will be storing the minimum // number of jumps required for // the position i. So DP[N+1] will // have the result we consider 0 // as source and N+1 as the destination int DP[N + 2]; // Base case (Steps to reach source is) DP[0] = 0; // Initialize all table values as Infinite for (int i = 1; i <= N + 1; i++) DP[i] = MAX; // Compute minimum jumps required // considering each Fibonacci // numbers one by one. // Go through each positions // till destination. for (int i = 1; i <= N + 1; i++) { // Calculate the minimum of that // position if all the Fibonacci // numbers are considered for (int j = 1; j < 30; j++) { // If the position is safe // or the position is the // destination then only we // calculate the minimum // otherwise the cost is // MAX as default if ((arr[i - 1] == 1 || i == N + 1) && i - fib[j] >= 0) DP[i] = min(DP[i], 1 + DP[i - fib[j]]); } } // -1 denotes if there is // no path possible if (DP[N + 1] != MAX) return DP[N + 1]; else return -1; } // Driver program to test above function int main() { int arr[] = { 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0 }; int n = sizeof(arr) / sizeof(arr[0]); cout << minJumps(arr, n); return 0; } Java `
// A Dynamic Programming based
// Java program to find minimum
// number of jumps to reach
// Destination
import java.util.;
import java.lang.;
class GFG
{
// Function that returns the min
// number of jump to reach the
// destination
public static int minJumps(int arr[], int N)
{
int MAX = 1000000;
// We consider only those Fibonacci
// numbers which are less than n,
// where we can consider fib[30]
// to be the upper bound as this
// will cross 10^5
int[] fib = new int[30];
fib[0] = 0;
fib[1] = 1;
for (int i = 2; i < 30; i++)
fib[i] = fib[i - 1] + fib[i - 2];
// DP[i] will be storing the minimum
// number of jumps required for
// the position i. So DP[N+1] will
// have the result we consider 0
// as source and N+1 as the destination
int[] DP = new int[N + 2];
// Base case (Steps to reach source is)
DP[0] = 0;
// Initialize all table values as Infinite
for (int i = 1; i <= N + 1; i++)
DP[i] = MAX;
// Compute minimum jumps required
// considering each Fibonacci
// numbers one by one.
// Go through each positions
// till destination.
for (int i = 1; i <= N + 1; i++)
{
// Calculate the minimum of that
// position if all the Fibonacci
// numbers are considered
for (int j = 1; j < 30; j++)
{
// If the position is safe
// or the position is the
// destination then only we
// calculate the minimum
// otherwise the cost is
// MAX as default
if ((i == N + 1 ||
arr[i - 1] == 1) &&
i - fib[j] >= 0)
DP[i] = Math.min(DP[i], 1 +
DP[i - fib[j]]);
}
}
// -1 denotes if there is
// no path possible
if (DP[N + 1] != MAX)
return DP[N + 1];
else
return -1; }
// Driver Code
public static void main (String[] args)
{
int[] arr = new int[]{ 0, 0, 0, 1, 1, 0,
1, 0, 0, 0, 0 };
int n = 11;
int ans = minJumps(arr, n);
System.out.println(ans);
}
}
// This code is contributed by MehulPython3
A Dynamic Programming based Python3 program
to find minimum number of jumps to reach
Destination
MAX = 1e9
Function that returns the min number
of jump to reach the destination
def minJumps(arr, N):
# We consider only those Fibonacci
# numbers which are less than n,
# where we can consider fib[30]
# to be the upper bound as this
# will cross 10^5
fib = [0 for i in range(30)]
fib[0] = 0
fib[1] = 1
for i in range(2, 30):
fib[i] = fib[i - 1] + fib[i - 2]
# DP[i] will be storing the minimum
# number of jumps required for
# the position i. So DP[N+1] will
# have the result we consider 0
# as source and N+1 as the destination
DP = [0 for i in range(N + 2)]
# Base case (Steps to reach source is)
DP[0] = 0
# Initialize all table values as Infinite
for i in range(1, N + 2):
DP[i] = MAX
# Compute minimum jumps required
# considering each Fibonacci
# numbers one by one.
# Go through each positions
# till destination.
for i in range(1, N + 2):
# Calculate the minimum of that
# position if all the Fibonacci
# numbers are considered
for j in range(1, 30):
# If the position is safe or the
# position is the destination then
# only we calculate the minimum
# otherwise the cost is MAX as default
if ((arr[i - 1] == 1 or i == N + 1) and
i - fib[j] >= 0):
DP[i] = min(DP[i], 1 + DP[i - fib[j]])
# -1 denotes if there is
# no path possible
if (DP[N + 1] != MAX):
return DP[N + 1]
else:
return -1 Driver Code
arr = [0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0]
n = len(arr)
print(minJumps(arr, n - 1))
This code is contributed by Mohit Kumar
C#
// A Dynamic Programming based
// C# program to find minimum
// number of jumps to reach
// Destination
using System;
using System.Collections.Generic;
class GFG
{
// Function that returns the min
// number of jump to reach the
// destination
public static int minJumps(int []arr, int N)
{
int MAX = 1000000;
// We consider only those Fibonacci
// numbers which are less than n,
// where we can consider fib[30]
// to be the upper bound as this
// will cross 10^5
int[] fib = new int[30];
fib[0] = 0;
fib[1] = 1;
for (int i = 2; i < 30; i++)
fib[i] = fib[i - 1] + fib[i - 2];
// DP[i] will be storing the minimum
// number of jumps required for
// the position i. So DP[N+1] will
// have the result we consider 0
// as source and N+1 as the destination
int[] DP = new int[N + 2];
// Base case (Steps to reach source is)
DP[0] = 0;
// Initialize all table values as Infinite
for (int i = 1; i <= N + 1; i++)
DP[i] = MAX;
// Compute minimum jumps required
// considering each Fibonacci
// numbers one by one.
// Go through each positions
// till destination.
for (int i = 1; i <= N + 1; i++)
{
// Calculate the minimum of that
// position if all the Fibonacci
// numbers are considered
for (int j = 1; j < 30; j++)
{
// If the position is safe
// or the position is the
// destination then only we
// calculate the minimum
// otherwise the cost is
// MAX as default
if ((i == N + 1 ||
arr[i - 1] == 1) &&
i - fib[j] >= 0)
DP[i] = Math.Min(DP[i], 1 +
DP[i - fib[j]]);
}
}
// -1 denotes if there is
// no path possible
if (DP[N + 1] != MAX)
return DP[N + 1];
else
return -1; }
// Driver Code
public static void Main (String[] args)
{
int[] arr = new int[]{ 0, 0, 0, 1, 1, 0,
1, 0, 0, 0, 0 };
int n = 11;
int ans = minJumps(arr, n);
Console.WriteLine(ans);
}
}
// This code is contributed by Princi SinghJavaScript
`
Time Complexity: O(Nlog(N))