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Diffstat (limited to 'make_sum_divisible_p.cpp')
-rw-r--r-- | make_sum_divisible_p.cpp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/make_sum_divisible_p.cpp b/make_sum_divisible_p.cpp new file mode 100644 index 0000000..993c955 --- /dev/null +++ b/make_sum_divisible_p.cpp @@ -0,0 +1,36 @@ +// 1590. Make Sum Divisible by P +#include "leetcode.h" + +/* + * given an array of positive integers 'nums', remove the smallest subarray + * (possibly empty) such that the sum of the remaining elements is divisible by + * 'p'. it is not allowed to remove the whole array. return the length of the + * smallest subarray that you need to remove, or -1 if it is impossible. a + * subarray is defined as a contiguous block of elements in the array. + */ + +class Solution { +public: + int minSubarray(vector<int> &nums, int p) { + int n = nums.size(), ans = n, req = 0, curr = 0; + for (auto i : nums) + req = (req + i) % p; + unordered_map<int, int> dp = {{0, -1}}; + for (int i = 0; i < n; i++) { + curr = (curr + nums[i]) % p; + dp[curr] = i; + int need = (curr - req + p) % p; + if (dp.count(need)) + ans = min(ans, i - dp[need]); + } + return ans < n ? ans : -1; + } +}; + +int main() { + Solution obj; + vector<int> n1 = {3, 1, 4, 2}, n2 = {6, 3, 5, 2}, n3 = {1, 2, 3}; + printf("%d\n", obj.minSubarray(n1, 6)); // expect: 1 + printf("%d\n", obj.minSubarray(n2, 9)); // expect: 2 + printf("%d\n", obj.minSubarray(n3, 3)); // expect: 0 +} |