leetcode - 209. 长度最小的子数组

#include 
#include 
using namespace std;

// 方法一：暴力法 
int minSubArrayLen1(int target, vector& nums) {
	int n = nums.size();
	if(n == 0){
		return 0;
	}
	if(nums[0] >= target){
		return 1;
	}
	int res = INT_MAX;
	int sum = 0, count = 0;
	for(int i = 1; i < n; i++){
		if(nums[i] >= target){
			res = 1;
			break;
		}
		sum += nums[i];
		count++;
		for(int j = i - 1; j >= 0; j--){
			sum += nums[j];
			count++;
			if(sum >= target){
				res = min(res, count);
				break;
			}
		}
		sum = 0;
		count = 0;
	}
	if(res == INT_MAX){
		res = 0;
	}
	return res;
}

// 方法二：滑动窗口 
int minSubArrayLen(int target, vector& nums) {
	int n = nums.size();
	if(n == 0){
		return 0;
	}
	if(nums[0] >= target){
		return 1;
	}
	int ans = INT_MAX;
	int left = 0, right = 0;
	int sum = 0;
	while(right < n){
		sum += nums[right];
		while(sum >= target){
			ans = min(ans, right - left + 1);
			sum -= nums[left];
			left++;
		}
		right++;
	}
	if(ans == INT_MAX){
		ans = 0;
	}
	return ans;
}

int main(){
	int n, target, res;
	cin>>n>>target;
	vector nums(n);
	for(int i = 0; i < n; i++){
		cin>>nums[i];
	}
	res = minSubArrayLen(target, nums);
	cout<