Serena211
diff --git a/‎bin/Class99_Mix/StringtoInteger.class‎
1.38 KB b/‎bin/Class99_Mix/StringtoInteger.class‎
1.38 KB
diff --git a/‎bin/Sort/SortColors.class‎
1.18 KB b/‎bin/Sort/SortColors.class‎
1.18 KB
diff --git a/‎bin/Sort/WiggleSort.class‎
483 Bytes b/‎bin/Sort/WiggleSort.class‎
483 Bytes
diff --git a/‎src/Class99_Mix/StringtoInteger.java‎
Lines changed: 51 additions & 0 deletions b/‎src/Class99_Mix/StringtoInteger.java‎
Lines changed: 51 additions & 0 deletions
diff --git a/‎src/Sort/SortColors.java‎
Lines changed: 58 additions & 0 deletions b/‎src/Sort/SortColors.java‎
Lines changed: 58 additions & 0 deletions
diff --git a/‎src/Sort/WiggleSort.java‎
Lines changed: 29 additions & 0 deletions b/‎src/Sort/WiggleSort.java‎
Lines changed: 29 additions & 0 deletions
@@ -0,0 +1,51 @@
+package Class99_Mix;
+
+// Implement atoi to convert a string to an integer.
+public class StringtoInteger {
+	public int myAtoi(String str) {
+		int index = str.length() - 1;
+		int sign = 1;
+		int total = 0;
+		// 1. Empty string
+		if (str == null || str.length() == 0) {
+			return 0;
+		}
+
+		//
+		int signCnt = 0;
+		for (int i = 0; i < str.length(); i++) {
+			if (str.charAt(i) == '+' || str.charAt(i) == '-') {
+				if (signCnt == 0) {
+					sign = str.charAt(i) == '+' ? 1 : -1;
+					signCnt++;
+				} else {
+					break;
+				}
+			} else if (isDigit(str.charAt(i))) {
+				// check overflow
+				if (Integer.MAX_VALUE < total * 10
+						|| Integer.MAX_VALUE / 10 == total
+						&& Integer.MAX_VALUE % 10 < str.charAt(i) - '0') {
+					return sign == 1 ? Integer.MAX_VALUE : Integer.MIN_VALUE;
+				}
+				total = total * 10 + str.charAt(i) - '0';
+			} else if (i>0 && (str.charAt(i) == ' ' && str.charAt(i-1) != ' ') || (str.charAt(i) != ' ' && str.charAt(i-1) != ' ') )  {
+				return total * sign;
+			}
+		}
+		return total * sign;
+	}
+
+	private boolean isDigit(char c) {
+		if (c < '0' || c > '9') {
+			return false;
+		}
+		return true;
+	}
+
+	public static void main(String[] args) {
+		StringtoInteger sol = new StringtoInteger();
+		System.out.println(sol.myAtoi("   +1222, 123 "));
+	}
+
+}
@@ -0,0 +1,58 @@
+package Sort;
+
+/*
+ * Given an array with n objects colored red, white or blue, sort them so that 
+ * objects of the same color are adjacent, with the colors in the order red, 
+ * white and blue.
+ * 
+ * Here, we will use the integers 0, 1, and 2 to represent the color red, white, 
+ * and blue respectively.
+ * 
+ * Note:
+ * You are not suppose to use the library's sort function for this problem.
+ */
+public class SortColors {
+	public void sortColors(int[] nums) {
+		if (nums == null || nums.length < 2) {
+			return;
+		}
+		// three pointers:
+		// red: 0 - red-th are red color
+		// white: red - white-th are white color
+		// ** white - blue-th are unknown area
+		// blue: blue - end are blue color
+		int red = 0;
+		int white = 0;
+		int blue = nums.length - 1;
+		for (int i = 0; i <= blue; i++) {
+			if (nums[i] == 0) {
+				swap(red, i, nums);
+				red++;
+				white++;
+			} else if (nums[i] == 1) {
+//				swap(white, i, nums);
+				white++;
+			} else {
+				swap(blue, i, nums);
+				blue--;
+				i--;
+			}
+		}
+	}
+
+	private void swap(int i, int j, int[] array) {
+		int temp = array[i];
+		array[i] = array[j];
+		array[j] = temp;
+
+	}
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		SortColors sol = new SortColors();
+		int[] nums = new int[] {0,1,1,2,1,2,0,0 };
+		sol.sortColors(nums);
+		System.out.println(nums.toString());
+	}
+
+}
@@ -0,0 +1,29 @@
+package Sort;
+
+/*
+ * Given an unsorted array nums, reorder it such that 
+ * nums[0] < nums[1] > nums[2] < nums[3]....
+ * 
+ * Example:
+ * (1) Given nums = [1, 5, 1, 1, 6, 4], one possible answer is [1, 4, 1, 5, 1, 6]. 
+ * (2) Given nums = [1, 3, 2, 2, 3, 1], one possible answer is [2, 3, 1, 3, 1, 2].
+ * 
+ * Note:
+ * You may assume all input has valid answer.
+ * Follow Up:
+ * Can you do it in O(n) time and/or in-place with O(1) extra space?
+ */
+public class WiggleSort {
+	public void wiggleSort(int[] nums) {
+//		divide(nums);
+	}
+
+
+	
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+
+	}
+
+}