Kattis Rank Climbing Notes
Martina DNA The core thinking is Sliding Window Algorithm. int findMinSubstringLength(const vector<int>& s, const unordered_map<int, int>& requiredCounts) { unordered_map<int, int> windowCounts; int minLength = INT_MAX; int left = 0, right = 0; int satisfied = 0; while (right < s.size()) { int rightInt = s[right]; if (requiredCounts.find(rightInt) != requiredCounts.end()) { windowCounts[rightInt]++; if (windowCounts[rightInt] == requiredCounts.at(rightInt)) { satisfied++; } } while (satisfied == requiredCounts.size()) { minLength = min(minLength, right - left + 1); int leftInt = s[left]; if (requiredCounts.find(leftInt) != requiredCounts.end()) { windowCounts[leftInt]--; if (windowCounts[leftInt] < requiredCounts.at(leftInt)) { satisfied--; } } left++; } right++; } return minLength == INT_MAX ? -1 : minLength; }