【题目】
The i
-th person has weight people[i]
, and each boat can carry a maximum weight of limit
.
Each boat carries at most 2 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. (It is guaranteed each person can be carried by a boat.)
船只能坐两人,有体重限制,找出最少船只数。
【思路】
贪心算法,sort排序数组,头尾指针p、q。
每次取最重的,如果未超过limit,【顺走】最轻的。
所以每次最重的尾指针q和答案ans必变化,轻的头指针p只在没超重时,即limit条件下减少。
【代码】
class Solution {
public int numRescueBoats(int[] people, int limit) {
Arrays.sort(people);
int p=0,q=people.length-1,ans=0;
while(p<=q){
ans++;
if(people[p]+people[q]<=limit){
p++;
}
q--;
}
return ans;
}
}
【例子】
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)