add 264, 304

Author: moranzcw

Algorithms/264.Ugly-Number-II/solution.cpp

@@ -0,0 +1,18 @@
+class Solution {
+public:
+    int nthUglyNumber(int n) {
+        vector<int> res(1, 1);
+        int i2 = 0, i3 = 0, i5 = 0;
+        while (res.size() < n) {
+            int m2 = res[i2] * 2; 
+            int m3 = res[i3] * 3; 
+            int m5 = res[i5] * 5;
+            int mn = min(m2, min(m3, m5));
+            if (mn == m2) ++i2;
+            if (mn == m3) ++i3;
+            if (mn == m5) ++i5;
+            res.push_back(mn);
+        }
+        return res.back();
+    }
+};

Algorithms/304.Range-Sum-Query-2D---Immutable/solution.cpp

@@ -0,0 +1,26 @@
+class NumMatrix {
+public:
+    vector<vector<int>> dp;
+    int row;
+    int col;
+    NumMatrix(vector<vector<int>> matrix) {
+        row = matrix.size();
+        col = row>0?matrix[0].size():0;
+        dp = vector<vector<int>>(row+1, vector<int>(col+1,0));
+        
+        //
+        for(int i=1;i<row+1;i++)
+            for(int j=1;j<col+1;j++)
+                dp[i][j] = matrix[i-1][j-1] + dp[i][j-1] + dp[i-1][j] - dp[i-1][j-1];
+    }
+    
+    int sumRegion(int row1, int col1, int row2, int col2) {
+        return dp[row2+1][col2+1] - dp[row2+1][col1] - dp[row1][col2+1] + dp[row1][col1];
+    }
+};
+
+/**
+ * Your NumMatrix object will be instantiated and called as such:
+ * NumMatrix obj = new NumMatrix(matrix);
+ * int param_1 = obj.sumRegion(row1,col1,row2,col2);
+ */

README.md

@@ -425,6 +425,8 @@
 
 [263.Ugly-Number](Algorithms/263.Ugly-Number/solution.cpp)
 
+[264.Ugly-Number-II](Algorithms/264.Ugly-Number-II/solution.cpp)
+
 [273.Integer-to-English-Words](Algorithms/273.Integer-to-English-Words/solution.cpp)
 
 [278.First-Bad-Version](Algorithms/278.First-Bad-Version/solution.cpp)
@@ -443,6 +445,8 @@
 
 [303.Range-Sum-Query---Immutable](Algorithms/303.Range-Sum-Query---Immutable/solution.cpp)
 
+[304.Range-Sum-Query-2D---Immutable](Algorithms/304.Range-Sum-Query-2D---Immutable/solution.cpp)
+
 [309.Best-Time-to-Buy-and-Sell-Stock-with-Cooldown](Algorithms/309.Best-Time-to-Buy-and-Sell-Stock-with-Cooldown/solution.cpp)
 
 [318.Maximum-Product-of-Word-Lengths](Algorithms/318.Maximum-Product-of-Word-Lengths/solution.cpp)