523.continuous-subarray-sum.java

/*
 * @lc app=leetcode id=523 lang=java
 *
 * [523] Continuous Subarray Sum
 *
 * https://leetcode.com/problems/continuous-subarray-sum/description/
 *
 * algorithms
 * Medium (24.18%)
 * Likes:    730
 * Dislikes: 952
 * Total Accepted:    71.2K
 * Total Submissions: 294.3K
 * Testcase Example:  '[23,2,4,6,7]\n6'
 *
 * Given a list of non-negative numbers and a target integer k, write a
 * function to check if the array has a continuous subarray of size at least 2
 * that sums up to a multiple of k, that is, sums up to n*k where n is also an
 * integer.
 * 
 * 
 * 
 * Example 1:
 * 
 * 
 * Input: [23, 2, 4, 6, 7],  k=6
 * Output: True
 * Explanation: Because [2, 4] is a continuous subarray of size 2 and sums up
 * to 6.
 * 
 * 
 * Example 2:
 * 
 * 
 * Input: [23, 2, 6, 4, 7],  k=6
 * Output: True
 * Explanation: Because [23, 2, 6, 4, 7] is an continuous subarray of size 5
 * and sums up to 42.
 * 
 * 
 * 
 * 
 * Note:
 * 
 * 
 * The length of the array won't exceed 10,000.
 * You may assume the sum of all the numbers is in the range of a signed 32-bit
 * integer.
 * 
 * 
 */
class Solution {
    public boolean checkSubarraySum(int[] nums, int k) {
        for (int i = 0; i < nums.length - 1; i++) {
            int sum = nums[i];
            for (int j = i + 1; j < nums.length; j++) {
                sum += nums[j];
                if (k != 0) {
                    if (sum % k == 0) {
                        return true;
                    }
                } else {
                    if (sum == 0) {
                        return true;
                    }
                }

            }
        }
        return false;
    }
}