g1301_1400.s1326_minimum_number_of_taps_to_open_to_water_a_garden

Class Solution

java.lang.Object

g1301_1400.s1326_minimum_number_of_taps_to_open_to_water_a_garden.Solution

public class Solution
extends Object

1326 - Minimum Number of Taps to Open to Water a Garden.

Hard

There is a one-dimensional garden on the x-axis. The garden starts at the point 0 and ends at the point n. (i.e The length of the garden is n).

There are n + 1 taps located at points [0, 1, ..., n] in the garden.

Given an integer n and an integer array ranges of length n + 1 where ranges[i] (0-indexed) means the i-th tap can water the area [i - ranges[i], i + ranges[i]] if it was open.

Return the minimum number of taps that should be open to water the whole garden, If the garden cannot be watered return -1.

Example 1:

Input: n = 5, ranges = [3,4,1,1,0,0]

Output: 1

Explanation: The tap at point 0 can cover the interval [-3,3]

The tap at point 1 can cover the interval [-3,5]

The tap at point 2 can cover the interval [1,3]

The tap at point 3 can cover the interval [2,4]

The tap at point 4 can cover the interval [4,4]

The tap at point 5 can cover the interval [5,5]

Opening Only the second tap will water the whole garden [0,5]

Example 2:

Input: n = 3, ranges = [0,0,0,0]

Output: -1

Explanation: Even if you activate all the four taps you cannot water the whole garden.

Constraints:

• 1 <= n <= 104
• ranges.length == n + 1
• 0 <= ranges[i] <= 100

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	minTaps(int n, int[] ranges)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

minTaps

public int minTaps(int n,
                   int[] ranges)