Add 279 code

0279-Perfect-Squares/cpp-0279/CMakeLists.txt

+cmake_minimum_required(VERSION 3.5)
+project(cpp_0279)
+
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+
+set(SOURCE_FILES main3.cpp)
+add_executable(cpp_0279 ${SOURCE_FILES})
\ No newline at end of file

0279-Perfect-Squares/cpp-0279/main.cpp

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+#include <iostream>
+#include <vector>
+#include <queue>
+#include <stdexcept>
+
+using namespace std;
+
+/// BFS
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+class Solution {
+public:
+    int numSquares(int n) {
+
+        if(n == 0)
+            return 0;
+
+        queue<pair<int, int>> q;
+        q.push(make_pair(n, 0));
+
+        vector<bool> visited(n + 1, false);
+        visited[n] = true;
+
+        while(!q.empty()){
+            int num = q.front().first;
+            int step = q.front().second;
+            q.pop();
+
+            for(int i = 1; num - i * i >= 0; i ++){
+                int a = num - i * i;
+                if(!visited[a]){
+                    if(a == 0) return step + 1;
+                    q.push(make_pair(a, step + 1));
+                    visited[a] = true;
+                }
+            }
+        }
+
+        throw invalid_argument("No Solution.");
+    }
+};
+
+int main() {
+
+    cout << Solution().numSquares(12) << endl;
+    cout << Solution().numSquares(13) << endl;
+
+    return 0;
+}
\ No newline at end of file

0279-Perfect-Squares/cpp-0279/main2.cpp

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/// Memory Search
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+class Solution {
+
+public:
+    int numSquares(int n) {
+
+        vector<int> mem(n + 1, -1);
+
+        return numSquares(n, mem);
+    }
+
+private:
+    int numSquares(int n, vector<int>& mem){
+
+        if(n == 0)
+            return 0;
+
+        if(mem[n] != -1)
+            return mem[n];
+
+        int res = INT_MAX;
+        for(int i = 1; n - i * i >= 0; i ++ )
+            res = min(res, 1 + numSquares(n - i * i, mem));
+        return mem[n] = res;
+    }
+};
+
+int main() {
+
+    cout << Solution().numSquares(12) << endl;
+    cout << Solution().numSquares(13) << endl;
+
+    return 0;
+}
\ No newline at end of file

0279-Perfect-Squares/cpp-0279/main3.cpp

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/// Dynamic Programming
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+class Solution {
+
+public:
+    int numSquares(int n) {
+
+        vector<int> mem(n + 1, INT_MAX);
+        mem[0] = 0;
+        for(int i = 1; i <= n ; i ++)
+            for(int j = 1 ; i - j * j >= 0 ; j ++)
+                mem[i] = min(mem[i], 1 + mem[i - j * j]);
+
+        return mem[n];
+    }
+};
+
+int main() {
+
+    cout << Solution().numSquares(12) << endl;
+    cout << Solution().numSquares(13) << endl;
+
+    return 0;
+}
\ No newline at end of file

0279-Perfect-Squares/java-0279/src/Solution1.java

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+import java.util.LinkedList;
+import javafx.util.Pair;
+
+/// BFS
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+public class Solution1 {
+
+    public int numSquares(int n) {
+
+        if(n == 0)
+            return 0;
+
+        LinkedList<Pair<Integer, Integer>> queue = new LinkedList<Pair<Integer, Integer>>();
+        queue.addLast(new Pair<Integer, Integer>(n, 0));
+
+        boolean[] visited = new boolean[n+1];
+        visited[n] = true;
+
+        while(!queue.isEmpty()){
+            Pair<Integer, Integer> front = queue.removeFirst();
+            int num = front.getKey();
+            int step = front.getValue();
+
+            if(num == 0)
+                return step;
+
+            for(int i = 1 ; num - i*i >= 0 ; i ++){
+                int a = num - i*i;
+                if(!visited[a]){
+                    if(a == 0) return step + 1;
+                    queue.addLast(new Pair(num - i * i, step + 1));
+                    visited[num - i * i] = true;
+                }
+            }
+        }
+
+        throw new IllegalStateException("No Solution.");
+    }
+
+    public static void main(String[] args) {
+
+        System.out.println((new Solution1()).numSquares(12));
+        System.out.println((new Solution1()).numSquares(13));
+    }
+}

0279-Perfect-Squares/java-0279/src/Solution2.java

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+import java.util.Arrays;
+
+/// Memory Search
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+public class Solution2 {
+
+    public int numSquares(int n) {
+
+        int[] mem = new int[n+1];
+        Arrays.fill(mem, -1);
+
+        return numSquares(n, mem);
+    }
+
+    private int numSquares(int n, int[] mem){
+
+        if(n == 0)
+            return 0;
+
+        if(mem[n] != -1)
+            return mem[n];
+
+        int res = Integer.MAX_VALUE;
+        for(int i = 1; n - i * i >= 0; i ++ )
+            res = Math.min(res, 1 + numSquares(n - i * i, mem));
+        return mem[n] = res;
+    }
+
+    public static void main(String[] args) {
+
+        System.out.println((new Solution2()).numSquares(12));
+        System.out.println((new Solution2()).numSquares(13));
+    }
+}

0279-Perfect-Squares/java-0279/src/Solution3.java

+/// Source : https://leetcode.com/problems/perfect-squares/description/
+/// Author : liuyubobobo
+/// Time   : 2017-11-17
+
+import java.util.Arrays;
+
+/// Dynamic Programming
+/// Time Complexity: O(n)
+/// Space Complexity: O(n)
+public class Solution3 {
+
+    public int numSquares(int n) {
+
+        int[] mem = new int[n+1];
+        Arrays.fill(mem, Integer.MAX_VALUE);
+        mem[0] = 0;
+        for(int i = 1; i <= n ; i ++)
+            for(int j = 1 ; i - j * j >= 0 ; j ++)
+                mem[i] = Math.min(mem[i], 1 + mem[i - j * j]);
+
+        return mem[n];
+    }
+
+    public static void main(String[] args) {
+
+        System.out.println((new Solution3()).numSquares(12));
+        System.out.println((new Solution3()).numSquares(13));
+    }
+}