add 169, 2554

Author: rustykitty

0169-majority-element.cpp

@@ -0,0 +1,23 @@
+/*
+169. Majority Element
+
+Submitted: December 5, 2024
+
+Runtime: 0 ms (beats 100.00%)
+Memory: 28.15 MB (beats 20.01%)
+*/
+
+class Solution {
+public:
+    int majorityElement(vector<int>& nums) {
+        unordered_map<int, int> map;
+        for ( const int num : nums ) {
+            map[num]++;
+        }
+        for ( auto& kv : map ) {
+            // problem statement says that floor(n / 2) is majority
+            if (kv.second > (nums.size() / 2)) return kv.first;
+        }
+        return -1;
+    }
+};

2554-maximum-number-of-integers-to-choose-from-a-range-i.cpp

@@ -0,0 +1,24 @@
+/*
+2554. Maximum Number of Integers to Choose From a Range I
+
+Submitted: December 5, 2024
+
+Runtime: 200 ms (beats 46.95%)
+Memory: 177.84 MB (beats 60.98)
+*/
+
+class Solution {
+public:
+    int maxCount(vector<int>& banned, int n, int maxSum) {
+        // set for O(1) operations
+        unordered_set<int> banned_set(banned.begin(), banned.end());
+        int sum(0);
+        int res(0);
+        for (int i = 1; i != n + 1 && sum + i <= maxSum; ++i) {
+            if (banned_set.count(i)) continue; // ignore banned numbers
+            ++res;
+            sum += (i);
+        }
+        return res;
+    }
+};