feat: add solutions to lc problem: No.1323 (#4648)

No.1323.Maximum 69 Number

Author: yanglbme

solution/1300-1399/1323.Maximum 69 Number/README.md

@@ -70,7 +70,7 @@ tags:
 
 我们将数组转换为字符串，然后从左到右遍历字符串，找到第一个出现的 $6$，将其替换为 $9$，然后返回转换后的字符串对应的整数即可。
 
-时间复杂度 $O(\log num)$，空间复杂度 $O(\log num)$。其中 $num$ 为给定的整数。
+时间复杂度 $O(\log \textit{num})$，空间复杂度 $O(\log \textit{num})$。其中 $\textit{num}$ 为给定的整数。
 
 <!-- tabs:start -->
 
@@ -114,15 +114,8 @@ public:
 
 ```go
 func maximum69Number(num int) int {
-	s := strconv.Itoa(num)
-	nums := []byte(s)
-	for i, ch := range nums {
-		if ch == '6' {
-			nums[i] = '9'
-			break
-		}
-	}
-	ans, _ := strconv.Atoi(string(nums))
+	s := strings.Replace(strconv.Itoa(num), "6", "9", 1)
+	ans, _ := strconv.Atoi(s)
 	return ans
 }
 ```
@@ -166,17 +159,17 @@ class Solution {
 
 ```c
 int maximum69Number(int num) {
-    int n = 0;
-    int i = 0;
-    int t = num;
-    while (t) {
-        n++;
-        if (t % 10 == 6) {
-            i = n;
+    char buf[12];
+    sprintf(buf, "%d", num);
+    for (int i = 0; buf[i] != '\0'; i++) {
+        if (buf[i] == '6') {
+            buf[i] = '9';
+            break;
         }
-        t /= 10;
     }
-    return num + 3 * pow(10, i - 1);
+    int ans;
+    sscanf(buf, "%d", &ans);
+    return ans;
 }
 ```
 

solution/1300-1399/1323.Maximum 69 Number/README_EN.md

@@ -29,7 +29,7 @@ tags:
 <pre>
 <strong>Input:</strong> num = 9669
 <strong>Output:</strong> 9969
-<strong>Explanation:</strong> 
+<strong>Explanation:</strong>
 Changing the first digit results in 6669.
 Changing the second digit results in 9969.
 Changing the third digit results in 9699.
@@ -67,7 +67,11 @@ The maximum number is 9969.
 
 <!-- solution:start -->
 
-### Solution 1
+### Solution 1: Greedy
+
+We convert the number to a string, then traverse the string from left to right to find the first occurrence of $6$, replace it with $9$, and then return the integer corresponding to the converted string.
+
+Time complexity $O(\log \textit{num})$, space complexity $O(\log \textit{num})$. Where $\textit{num}$ is the given integer.
 
 <!-- tabs:start -->
 
@@ -111,15 +115,8 @@ public:
 
 ```go
 func maximum69Number(num int) int {
-	s := strconv.Itoa(num)
-	nums := []byte(s)
-	for i, ch := range nums {
-		if ch == '6' {
-			nums[i] = '9'
-			break
-		}
-	}
-	ans, _ := strconv.Atoi(string(nums))
+	s := strings.Replace(strconv.Itoa(num), "6", "9", 1)
+	ans, _ := strconv.Atoi(s)
 	return ans
 }
 ```
@@ -163,17 +160,17 @@ class Solution {
 
 ```c
 int maximum69Number(int num) {
-    int n = 0;
-    int i = 0;
-    int t = num;
-    while (t) {
-        n++;
-        if (t % 10 == 6) {
-            i = n;
+    char buf[12];
+    sprintf(buf, "%d", num);
+    for (int i = 0; buf[i] != '\0'; i++) {
+        if (buf[i] == '6') {
+            buf[i] = '9';
+            break;
         }
-        t /= 10;
     }
-    return num + 3 * pow(10, i - 1);
+    int ans;
+    sscanf(buf, "%d", &ans);
+    return ans;
 }
 ```
 

solution/1300-1399/1323.Maximum 69 Number/Solution.c

@@ -1,13 +1,13 @@
 int maximum69Number(int num) {
-    int n = 0;
-    int i = 0;
-    int t = num;
-    while (t) {
-        n++;
-        if (t % 10 == 6) {
-            i = n;
+    char buf[12];
+    sprintf(buf, "%d", num);
+    for (int i = 0; buf[i] != '\0'; i++) {
+        if (buf[i] == '6') {
+            buf[i] = '9';
+            break;
         }
-        t /= 10;
     }
-    return num + 3 * pow(10, i - 1);
-}
+    int ans;
+    sscanf(buf, "%d", &ans);
+    return ans;
+}

solution/1300-1399/1323.Maximum 69 Number/Solution.go

@@ -1,12 +1,5 @@
 func maximum69Number(num int) int {
-	s := strconv.Itoa(num)
-	nums := []byte(s)
-	for i, ch := range nums {
-		if ch == '6' {
-			nums[i] = '9'
-			break
-		}
-	}
-	ans, _ := strconv.Atoi(string(nums))
+	s := strings.Replace(strconv.Itoa(num), "6", "9", 1)
+	ans, _ := strconv.Atoi(s)
 	return ans
-}
+}