LeetCode/cpp/subarray-product-less-than-k.cpp

#include <vector>

class Solution {
  public:
    int numSubarrayProductLessThanK(const std::vector<int> &nums, int k) {
        if (k <= 1) {
            return 0;
        }

        int count = 0;
        int product = 1;
        for (std::size_t i = 0, j = 0; j < nums.size(); ++j) {
            product *= nums[j];

            for (; product >= k; ++i) {
                product /= nums[i];
            }

            count += j - i + 1;
        }

        return count;
    }
};

#ifdef _MF_TEST
#include <gtest/gtest.h>

TEST(examples, _1) {
    Solution s;
    EXPECT_EQ(s.numSubarrayProductLessThanK(std::vector{10, 5, 2, 6}, 100), 8);
}

TEST(examples, _2) {
    Solution s;
    EXPECT_EQ(s.numSubarrayProductLessThanK(std::vector{1, 2, 3}, 0), 0);
}

int main(int argc, char **argv) {
    testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}
#endif