feat: update solutions to lcci problem: No.01.01. Is Unique

Author: yanglbme

lcci/01.01.Is Unique/README.md

@@ -59,8 +59,8 @@ class Solution:
 class Solution {
     public boolean isUnique(String astr) {
         int bitmap = 0;
-        for (int i = 0, n = astr.length(); i < n; ++i) {
-            int pos = astr.charAt(i) - 'a';
+        for (char c : astr.toCharArray()) {
+            int pos = c - 'a';
             if ((bitmap & (1 << pos)) != 0) {
                 return false;
             }
@@ -107,6 +107,25 @@ func isUnique(astr string) bool {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    bool isUnique(string astr) {
+        int bitmap = 0;
+        for (char c : astr) {
+            int pos = c - 'a';
+            if ((bitmap & (1 << pos)) != 0) {
+                return false;
+            }
+            bitmap |= (1 << pos);
+        }
+        return true;
+    }
+};
+```
+
 ### **...**
 
 ```

lcci/01.01.Is Unique/README_EN.md

@@ -56,8 +56,8 @@ class Solution:
 class Solution {
     public boolean isUnique(String astr) {
         int bitmap = 0;
-        for (int i = 0, n = astr.length(); i < n; ++i) {
-            int pos = astr.charAt(i) - 'a';
+        for (char c : astr.toCharArray()) {
+            int pos = c - 'a';
             if ((bitmap & (1 << pos)) != 0) {
                 return false;
             }
@@ -104,6 +104,25 @@ func isUnique(astr string) bool {
 }
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    bool isUnique(string astr) {
+        int bitmap = 0;
+        for (char c : astr) {
+            int pos = c - 'a';
+            if ((bitmap & (1 << pos)) != 0) {
+                return false;
+            }
+            bitmap |= (1 << pos);
+        }
+        return true;
+    }
+};
+```
+
 ### **...**
 
 ```

lcci/01.01.Is Unique/Solution.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+    bool isUnique(string astr) {
+        int bitmap = 0;
+        for (char c : astr) {
+            int pos = c - 'a';
+            if ((bitmap & (1 << pos)) != 0) {
+                return false;
+            }
+            bitmap |= (1 << pos);
+        }
+        return true;
+    }
+};

lcci/01.01.Is Unique/Solution.java

@@ -1,8 +1,8 @@
 class Solution {
     public boolean isUnique(String astr) {
         int bitmap = 0;
-        for (int i = 0, n = astr.length(); i < n; ++i) {
-            int pos = astr.charAt(i) - 'a';
+        for (char c : astr.toCharArray()) {
+            int pos = c - 'a';
             if ((bitmap & (1 << pos)) != 0) {
                 return false;
             }