Algorithm
Problem Name: 849. Maximize Distance to Closest Person
You are given an array representing a row of seats where seats[i] = 1 represents a person sitting in the ith seat, and seats[i] = 0 represents that the ith seat is empty (0-indexed).
There is at least one empty seat, and at least one person sitting.
Alex wants to sit in the seat such that the distance between him and the closest person to him is maximized.
Return that maximum distance to the closest person.
Example 1:
Input: seats = [1,0,0,0,1,0,1] Output: 2 Explanation: If Alex sits in the second open seat (i.e. seats[2]), then the closest person has distance 2. If Alex sits in any other open seat, the closest person has distance 1. Thus, the maximum distance to the closest person is 2.
Example 2:
Input: seats = [1,0,0,0] Output: 3 Explanation: If Alex sits in the last seat (i.e. seats[3]), the closest person is 3 seats away. This is the maximum distance possible, so the answer is 3.
Example 3:
Input: seats = [0,1] Output: 1
Constraints:
2 <= seats.length <= 2 * 104seats[i]is0or1.- At least one seat is empty.
- At least one seat is occupied.
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
int maxDistToClosest(vector<int>& seats) {
int res = -1, d = 0;
for(auto x: seats) if(x) res = max(res, res == -1 ? d : d/2), d = 1; else d++;
return max(res, d - 1);
}
};
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Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
public int maxDistToClosest(int[] seats) {
int n = seats.length;
int maxDistance = 0;
int start = -1;
for (int i = 0; i < n; i++) {
if (seats[i] == 1) {
maxDistance = start == -1 ? i : Math.max(maxDistance, (i - start) / 2);
start = i;
}
}
return Math.max(maxDistance, n - 1 - start);
}
}
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Output
#3 Code Example with Javascript Programming
Code -
Javascript Programming
const maxDistToClosest = function(seats) {
let left, right, res = 0, n = seats.length;
for (left = right = 0; right < n; ++right)
if (seats[right] === 1) {
if (left === 0) res = Math.max(res, right - left);
else res = Math.max(res, Math.floor((right - left + 1) / 2));
left = right + 1;
}
res = Math.max(res, n - left);
return res;
};
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#4 Code Example with Python Programming
Code -
Python Programming
class Solution:
def maxDistToClosest(self, seats):
d = {}
res = l = left = r = right = 0
for i, s in enumerate(seats):
if not s and left: d[i] = l = l + 1
elif s: l, left = 0, 1
for i in range(len(seats) - 1, -1, -1):
if not seats[i] and right and (i not in d or d[i] > r): d[i] = r = r + 1
elif seats[i]: r, right = 0, 1
return max(d.values())
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#5 Code Example with C# Programming
Code -
C# Programming
using System;
namespace LeetCode
{
public class _0849_MaximizeDistanceToClosestPerson
{
public int MaxDistToClosest(int[] seats)
{
int k = 0, n = seats.Length;
var result = 0;
for (int i = 0; i < n; i++)
{
if (seats[i] == 1)
k = 0;
else
{
k++;
result = Math.Max(result, (k + 1) / 2);
}
}
for (int i = 0; i < n; i++)
{
if (seats[i] == 1)
{
result = Math.Max(result, i);
break;
}
}
for (int i = n - 1; i >= 0; i--)
{
if (seats[i] == 1)
{
result = Math.Max(result, n - i - 1);
break;
}
}
return result;
}
}
}
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Output