add: 221026-CN

cpp/2210/221026-CN.cpp

@@ -0,0 +1,42 @@
+#include <vector>
+#include <utility>
+#include <algorithm>
+#include <iostream>
+
+/**
+ * 862. Shortest Subarray with Sum at Least K
+ *
+ * Given an integer array nums and an integer k, return the length of the shortest non-empty subarray of nums with a sum of at least k. If there is no such subarray, return -1.
+ * A subarray is a contiguous part of an array.
+ */
+
+class Solution {
+public:
+	static int shortestSubarray(const std::vector<int>& nums, int k) {
+		const int n = nums.size();
+		auto ans = unsigned(-1);
+		long long s[100008]{0}, sum = 0;
+		int t[100008]{-1}, pos = 1;
+		for (int i = 0; i < n; ++i) {
+			// pos -> i, current -> sum + nums[i]
+			sum += nums[i];
+			// Check whether it has OK solution
+			if (nums[i] > 0) {
+				auto it = std::upper_bound(s, s + pos, sum - k);
+				if (it == s + pos || it != s && *it > sum - k)
+					--it;
+				if (*it <= sum - k && 1 == (ans = std::min(ans, unsigned(i - t[it - s]))))
+					return 1;
+			}
+			while (pos && s[pos - 1] >= sum)
+				--pos;
+			s[pos] = sum;
+			t[pos++] = i;
+		}
+		return int(ans);
+	}
+};
+
+int main() {
+	std::cout << Solution::shortestSubarray({2, -1, 2}, 3);
+}

cpp/2210/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2210)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2210 221025.cpp)
+ADD_EXECUTABLE(2210 221026-CN.cpp)