add new files

Author: anakin

71. Simplify Path.go

@@ -0,0 +1,36 @@
+package main
+
+import "strings"
+
+func simplifyPath(path string) string {
+	dirs := strings.FieldsFunc(path, func(s rune) bool {
+		if s == '/' {
+			return true
+		}
+		return false
+	})
+	for i := 0; i < len(dirs); i++ {
+		if dirs[i] == "." {
+			dirs = append(dirs[:i], dirs[i+1:]...)
+			i--
+		} else {
+			if dirs[i] == ".." {
+				if i == 0 {
+					dirs = dirs[1:]
+					i--
+					continue
+				}
+				dirs = append(dirs[:i-1], dirs[i+1:]...)
+				i -= 2
+			}
+		}
+	}
+	res := "/"
+	for i := 0; i < len(dirs); i++ {
+		res += dirs[i]
+		if i != len(dirs)-1 {
+			res += "/"
+		}
+	}
+	return res
+}

79. Word Search.go

@@ -0,0 +1,47 @@
+package main
+
+func help(b [][]byte, word string, i, j int) bool {
+	if word == "" {
+		return true
+	}
+	if b[i][j] != word[0] {
+		return false
+	}
+	if len(word) == 1 {
+		return true
+	}
+	b[i][j] = '#'
+	if i > 0 && help(b, word[1:], i-1, j) {
+		return true
+	}
+	if j > 0 && help(b, word[1:], i, j-1) {
+		return true
+	}
+	if i < len(b)-1 && help(b, word[1:], i+1, j) {
+		return true
+	}
+	if j < len(b[0])-1 && help(b, word[1:], i, j+1) {
+		return true
+	}
+	b[i][j] = word[0]
+	return false
+}
+func exist(board [][]byte, word string) bool {
+	if len(board) == 0 || len(board[0]) == 0 {
+		return word == ""
+	}
+	if word == "" {
+		return true
+	}
+	for i := 0; i < len(board); i++ {
+		for j := 0; j < len(board[0]); j++ {
+			if word[0] != board[i][j] {
+				continue
+			}
+			if help(board, word, i, j) {
+				return true
+			}
+		}
+	}
+	return false
+}

81. Search in Rotated Sorted Array II.go

@@ -0,0 +1,31 @@
+package main
+
+func search(nums []int, target int) bool {
+	l := len(nums)
+	if l == 0 {
+		return false
+	}
+	left, right := 0, l-1
+	for left <= right {
+		mid := left + (right-left)/2
+		if nums[mid] == target {
+			return true
+		} else if nums[mid] < nums[right] {
+			if nums[mid] < target && nums[right] >= target {
+				left = mid + 1
+			} else {
+				right = mid - 1
+			}
+		} else if nums[mid] > nums[right] {
+			if nums[left] <= target && nums[mid] > target {
+				right = mid - 1
+			} else {
+				left = mid + 1
+			}
+		} else {
+			right--
+		}
+
+	}
+	return false
+}