Algorithm
Problem Name: 881. Boats to Save People
You are given an array people where people[i] is the weight of the ith person, and an infinite number of boats where each boat can carry a maximum weight of limit. Each boat carries at most two people at the same time, provided the sum of the weight of those people is at most limit.
Return the minimum number of boats to carry every given person.
Example 1:
Input: people = [1,2], limit = 3 Output: 1 Explanation: 1 boat (1, 2)
Example 2:
Input: people = [3,2,2,1], limit = 3 Output: 3 Explanation: 3 boats (1, 2), (2) and (3)
Example 3:
Input: people = [3,5,3,4], limit = 5 Output: 4 Explanation: 4 boats (3), (3), (4), (5)
Constraints:
1 <= people.length <= 5 * 1041 <= people[i] <= limit <= 3 * 104
Code Examples
#1 Code Example with Javascript Programming
Code -
Javascript Programming
const numRescueBoats = function(people, limit) {
if(people.length === 0) return 0
const arr = people.sort((a, b) => a - b)
let count = 0
let i = 0
let j = arr.length - 1
while(i <= j) {
count++
if(arr[i] + arr[j] < = limit> {
i++
}
j--
}
return count
};
Input
people = [1,2], limit = 3
Output
1
#2 Code Example with Python Programming
Code -
Python Programming
class Solution:
def numRescueBoats(self, people, limit):
"""
:type people: List[int]
:type limit: int
:rtype: int
"""
people.sort()
l, r, cnt = 0, len(people) - 1, 0
while l <= r:
if l != r and people[l] + people[r] > limit: l -= 1
l += 1
r -= 1
cnt += 1
return cnt
Input
people = [1,2], limit = 3
Output
1