Question 4
Street Lights are installed at every position along a 1-D road of length n.
Locations[] (an array) represents the coverage limit of these lights. The ith light has a coverage limit of locations[i] that can range from the position max((i – locations[i]), 1) to min((i + locations[i]), n ) (Closed intervals). Initially all the lights are switched off. Find the minimum number of fountains that must be switched on to cover the road.
Example
n = 3
locations[] = {0, 2, 13}then
For position 1: locations[1] = 0, max((1 – 0),
1) to mini (1+0), 3) gives range = 1 to 1
For position 2: locations[2] = 2, max((2-2),
1) to min( (2+2), 3) gives range = 1 to 3
For position 3: locations[3] = 1, max( (3-1),
1) to min( (3+1), 3) gives range = 2 to 3
For the entire length of this road to be covered, only the light at position 2 needs to be activated.
Function Description
Returns
int: the minimum number of street lights that must be activated
Constraints
- 1<_n<_ 10^5
- O<_locations[i] <_ mini (n,100) (where 1 <_1<_
10^5)
► Input Format For Custom Testing
Sample Case 0
Sample Input For Custom Testing
3 ->locations[] size n = 3
1 ->locations[] [1, 1, 1]
1 ->Sample Output
Sample Output
1
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