Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k.
Example 1:
Input:nums = [1,1,1], k = 2 Output: 2
Note:
- The length of the array is in range [1, 20,000].
- The range of numbers in the array is [-1000, 1000] and the range of the integer k is [-1e7, 1e7].
Solution:
class Solution {
public:
int subarraySum(vector<int>& nums, int k) {
int res = 0, n = nums.size();
for (int i = 0; i < n; ++i) {
int sum = nums[i];
if (sum == k) ++res;
for (int j = i + 1; j < n; ++j) {
sum += nums[j];
if (sum == k) ++res;
}
}
return res;
}
};