add 274,324,746,914,915

Author: moranzcw

Algorithms/274.H-Index/solution.cpp

@@ -0,0 +1,16 @@
+bool cmp(int i, int j){
+    return i>j;
+}
+
+class Solution {
+public:
+    int hIndex(vector<int>& citations) {
+        sort(citations.begin(),citations.end(),cmp);
+        int i;
+        for(i=0;i<citations.size();i++){
+            if(citations[i]<(i+1))
+                return i;
+        }
+        return i;
+    }
+};

Algorithms/324.Wiggle-Sort-II/solution.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    void wiggleSort(vector<int>& nums) {
+        int n = nums.size();
+    
+        // Find a median.
+        auto midptr = nums.begin() + n / 2;
+        nth_element(nums.begin(), midptr, nums.end());
+        int mid = *midptr;
+
+        // Index-rewiring.
+        #define A(i) nums[(1+2*(i)) % (n|1)]
+
+        // 3-way-partition-to-wiggly in O(n) time with O(1) space.
+        int i = 0, j = 0, k = n - 1;
+        while (j <= k) {
+            if (A(j) > mid)
+                swap(A(i++), A(j++));
+            else if (A(j) < mid)
+                swap(A(j), A(k--));
+            else
+                j++;
+        }
+    }
+};

Algorithms/746.Min-Cost-Climbing-Stairs/solution.cpp

@@ -0,0 +1,16 @@
+class Solution {
+public:
+    int minCostClimbingStairs(vector<int>& cost) {
+        vector<int> dp(cost.size(),0);
+        int dp1 = cost[0];
+        int dp2 = cost[1];
+        int cur;
+        for(int i=2;i<cost.size();i++){
+           cur = min(dp1,dp2) + cost[i];
+            dp1 = dp2;
+            dp2 = cur;
+        }
+        
+        return min(dp1,dp2);
+    }
+};

Algorithms/914.X-of-a-Kind-in-a-Deck-of-Cards/solution.cpp

@@ -0,0 +1,37 @@
+class Solution {
+public:
+    int get_gcd(int a, int b) {
+        int h = max(a, b);
+        int l = min(a, b);
+        
+        if (l == 0) return h;
+        
+        int m = h % l;
+        
+        while (m) {
+            h = l;
+            l = m;
+            m = h % l;
+        }
+        return l;
+    }
+    
+    bool hasGroupsSizeX(vector<int>& deck) {
+        map<int, int> count;
+        
+        for(auto i:deck){
+            if(count.find(i) != count.end())
+                count[i] += 1;
+            else
+                count[i] = 1;
+        }
+        
+        int min_gcd = count.begin()->second;
+        int last = min_gcd;
+        for(auto i=count.begin();i!=count.end();i++){
+            min_gcd = min(min_gcd, get_gcd(i->second,last));
+            last = i->second;
+        }
+        return min_gcd>=2;
+    }
+};

Algorithms/915.Partition-Array-into-Disjoint-Intervals/solution.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    int partitionDisjoint(vector<int>& A) {
+        vector<int> max_left(A.size());
+        vector<int> min_right(A.size());
+        max_left[0] = A[0];
+        for(int i=1;i<max_left.size();i++){
+            max_left[i] = max(A[i],max_left[i-1]);
+        }
+        
+        min_right.back() = A.back();
+        for(int i=min_right.size()-2;i>=0;i--){
+            min_right[i] = min(A[i],min_right[i+1]);
+        }
+        
+        for(int i=0;i<A.size()-1;i++){
+            if(max_left[i]<=min_right[i+1])
+                return i+1;
+        }
+        return 0;
+    }
+};

README.md

@@ -429,6 +429,8 @@
 
 [273.Integer-to-English-Words](Algorithms/273.Integer-to-English-Words/solution.cpp)
 
+[274.H-Index](Algorithms/274.H-Index/solution.cpp)
+
 [278.First-Bad-Version](Algorithms/278.First-Bad-Version/solution.cpp)
 
 [283.Move-Zeroes](Algorithms/283.Move-Zeroes/solution.cpp)
@@ -453,6 +455,8 @@
 
 [319.Bulb-Switcher](Algorithms/319.Bulb-Switcher/solution.cpp)
 
+[324.Wiggle-Sort-II](Algorithms/324.Wiggle-Sort-II/solution.cpp)
+
 [326.Power-of-Three](Algorithms/326.Power-of-Three/solution.cpp)
 
 [328.Odd-Even-Linked-List](Algorithms/328.Odd-Even-Linked-List/solution.cpp)
@@ -579,6 +583,8 @@
 
 [680.Valid-Palindrome-II](Algorithms/680.Valid-Palindrome-II/solution.cpp)
 
+[746.Min-Cost-Climbing-Stairs](Algorithms/746.Min-Cost-Climbing-Stairs/solution.cpp)
+
 [762.Prime-Number-of-Set-Bits-in-Binary-Representation](Algorithms/762.Prime-Number-of-Set-Bits-in-Binary-Representation/solution.cpp)
 
 [824.Goat-Latin](Algorithms/824.Goat-Latin/solution.cpp)
@@ -589,6 +595,10 @@
 
 [897.Increasing-Order-Search-Tree](Algorithms/897.Increasing-Order-Search-Tree/solution.cpp)
 
+[914.X-of-a-Kind-in-a-Deck-of-Cards](Algorithms/914.X-of-a-Kind-in-a-Deck-of-Cards/solution.cpp)
+
+[915.Partition-Array-into-Disjoint-Intervals](Algorithms/915.Partition-Array-into-Disjoint-Intervals/solution.cpp)
+
 [925.Long-Pressed-Name](Algorithms/925.Long-Pressed-Name/solution.cpp)
 
 [926.Flip-String-to-Monotone-Increasing](Algorithms/926.Flip-String-to-Monotone-Increasing/solution.cpp)