救生艇(双指针)-C语言

救生艇(双指针)

#include 

void quick_sort(int *a, int left, int right);
int numRescueBoats(int* people, int peopleSize, int limit);

int main()
{
	int people[2] = {3, 2, 2, 1};
	int limit = 3;
	int nums = numRescueBoats(people, 4, 3);
	printf("需要%d个救生艇", nums);
}
//快速排序
void quick_sort(int *a, int left, int right)
{
    int i, j, t, temp;
	if(left >= right)
		return;
	temp = a[left];
	i = left;
	j = right;
	while(i != j)
	{
		while(a[j] >= temp && i < j)
		{
			j--;
		}
		while(a[i] <= temp && i < j)
		{
			i++;
		}
		if(i < j)
		{
			t = a[i];
			a[i] = a[j];
			a[j] = t;
		}
	}
	a[left] = a[i];
	a[i] = temp;
	quick_sort(a, left, i-1);
	quick_sort(a, i+1, right);
	return;
}
//leetcode-881
int numRescueBoats(int* people, int peopleSize, int limit)
{
    quick_sort(people, 0, peopleSize-1);
    int nums = 0;
	int left = 0;
	int right = peopleSize - 1;
	while(left <= right)
	{
		if(people[left] + people[right] <= limit)
			left++;
		right--;
		nums++;
	}
    return nums;
}