feat: add solutions to lc problem: No.1805

yanglbme · yanglbme · commit 8dcb46281c43 · 2022-10-06T16:29:35.000+08:00
No.1805.Number of Different Integers in a String
diff --git a/solution/1200-1299/1249.Minimum Remove to Make Valid Parentheses/README_EN.md b/solution/1200-1299/1249.Minimum Remove to Make Valid Parentheses/README_EN.md
@@ -141,7 +141,7 @@ public:
             if (c == ')') ++x;
             else if (c == '(') --x;
             ans.push_back(c);
-        }   
+        }
         reverse(ans.begin(), ans.end());
         return ans;
     }
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/README.md b/solution/1800-1899/1805.Number of Different Integers in a String/README.md
@@ -52,7 +52,15 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
-将 `word` 按照字母切分，得到数字数组 `nums`，然后利用 set 去重，返回 set 的长度即可。
+**方法一：双指针 + 模拟**
+
+遍历字符串，找到每个整数的起始位置和结束位置，截取出这一个子串，将其存入哈希表 `s` 中。
+
+最后返回哈希表 `s` 的大小即可。
+
+注意，这里要去掉整数的前导零，并且不能直接将字符串转为整数，因为整数可能很大，超出 `int` 的范围。
+
+时间复杂度 $O(n)$，空间复杂度 $O(n)$。其中 $n$ 为字符串 `word` 的长度。
 
 <!-- tabs:start -->
 
@@ -61,13 +69,21 @@
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
-import re
-
-
 class Solution:
     def numDifferentIntegers(self, word: str) -> int:
-        nums = re.split(r'[a-z]+', word)
-        return len({int(num) for num in nums if num != ''})
+        s = set()
+        i, n = 0, len(word)
+        while i < n:
+            if word[i].isdigit():
+                while i < n and word[i] == '0':
+                    i += 1
+                j = i
+                while j < n and word[j].isdigit():
+                    j += 1
+                s.add(word[i: j])
+                i = j
+            i += 1
+        return len(s)
 ```
 
 ### **Java**
@@ -77,20 +93,72 @@ class Solution:
 ```java
 class Solution {
     public int numDifferentIntegers(String word) {
-        String[] nums = word.split("[a-z]+");
-        Set<String> numSet = new HashSet<>();
-        for (String num : nums) {
-            if ("".equals(num)) {
-                continue;
+        Set<String> s = new HashSet<>();
+        int n = word.length();
+        for (int i = 0; i < n; ++i) {
+            if (Character.isDigit(word.charAt(i))) {
+                while (i < n && word.charAt(i) == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && Character.isDigit(word.charAt(j))) {
+                    ++j;
+                }
+                s.add(word.substring(i, j));
+                i = j;
             }
-            int j = 0;
-            while (j < num.length() - 1 && num.charAt(j) == '0') {
-                ++j;
+        }
+        return s.size();
+    }
+}
+```
+
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int numDifferentIntegers(string word) {
+        unordered_set<string> s;
+        int n = word.size();
+        for (int i = 0; i < n; ++i) {
+            if (isdigit(word[i])) {
+                while (i < n && word[i] == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && isdigit(word[j])) {
+                    ++j;
+                }
+                s.insert(word.substr(i, j - i));
+                i = j;
             }
-            numSet.add(num.substring(j));
         }
-        return numSet.size();
+        return s.size();
     }
+};
+```
+
+### **Go**
+
+```go
+func numDifferentIntegers(word string) int {
+	s := map[string]struct{}{}
+	n := len(word)
+	for i := 0; i < n; i++ {
+		if word[i] >= '0' && word[i] <= '9' {
+			for i < n && word[i] == '0' {
+				i++
+			}
+			j := i
+			for j < n && word[j] >= '0' && word[j] <= '9' {
+				j++
+			}
+			s[word[i:j]] = struct{}{}
+			i = j
+		}
+	}
+	return len(s)
 }
 ```
 
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/README_EN.md b/solution/1800-1899/1805.Number of Different Integers in a String/README_EN.md
@@ -52,34 +52,94 @@ the leading zeros are ignored when comparing their decimal values.
 ### **Python3**
 
 ```python
-import re
-
-
 class Solution:
     def numDifferentIntegers(self, word: str) -> int:
-        nums = re.split(r'[a-z]+', word)
-        return len({int(num) for num in nums if num != ''})
+        s = set()
+        i, n = 0, len(word)
+        while i < n:
+            if word[i].isdigit():
+                while i < n and word[i] == '0':
+                    i += 1
+                j = i
+                while j < n and word[j].isdigit():
+                    j += 1
+                s.add(word[i: j])
+                i = j
+            i += 1
+        return len(s)
 ```
 
 ### **Java**
 
 ```java
 class Solution {
     public int numDifferentIntegers(String word) {
-        String[] nums = word.split("[a-z]+");
-        Set<String> numSet = new HashSet<>();
-        for (String num : nums) {
-            if ("".equals(num)) {
-                continue;
+        Set<String> s = new HashSet<>();
+        int n = word.length();
+        for (int i = 0; i < n; ++i) {
+            if (Character.isDigit(word.charAt(i))) {
+                while (i < n && word.charAt(i) == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && Character.isDigit(word.charAt(j))) {
+                    ++j;
+                }
+                s.add(word.substring(i, j));
+                i = j;
             }
-            int j = 0;
-            while (j < num.length() - 1 && num.charAt(j) == '0') {
-                ++j;
+        }
+        return s.size();
+    }
+}
+```
+
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int numDifferentIntegers(string word) {
+        unordered_set<string> s;
+        int n = word.size();
+        for (int i = 0; i < n; ++i) {
+            if (isdigit(word[i])) {
+                while (i < n && word[i] == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && isdigit(word[j])) {
+                    ++j;
+                }
+                s.insert(word.substr(i, j - i));
+                i = j;
             }
-            numSet.add(num.substring(j));
         }
-        return numSet.size();
+        return s.size();
     }
+};
+```
+
+### **Go**
+
+```go
+func numDifferentIntegers(word string) int {
+	s := map[string]struct{}{}
+	n := len(word)
+	for i := 0; i < n; i++ {
+		if word[i] >= '0' && word[i] <= '9' {
+			for i < n && word[i] == '0' {
+				i++
+			}
+			j := i
+			for j < n && word[j] >= '0' && word[j] <= '9' {
+				j++
+			}
+			s[word[i:j]] = struct{}{}
+			i = j
+		}
+	}
+	return len(s)
 }
 ```
 
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/Solution.cpp b/solution/1800-1899/1805.Number of Different Integers in a String/Solution.cpp
@@ -0,0 +1,21 @@
+class Solution {
+public:
+    int numDifferentIntegers(string word) {
+        unordered_set<string> s;
+        int n = word.size();
+        for (int i = 0; i < n; ++i) {
+            if (isdigit(word[i])) {
+                while (i < n && word[i] == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && isdigit(word[j])) {
+                    ++j;
+                }
+                s.insert(word.substr(i, j - i));
+                i = j;
+            }
+        }
+        return s.size();
+    }
+};
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/Solution.go b/solution/1800-1899/1805.Number of Different Integers in a String/Solution.go
@@ -0,0 +1,18 @@
+func numDifferentIntegers(word string) int {
+	s := map[string]struct{}{}
+	n := len(word)
+	for i := 0; i < n; i++ {
+		if word[i] >= '0' && word[i] <= '9' {
+			for i < n && word[i] == '0' {
+				i++
+			}
+			j := i
+			for j < n && word[j] >= '0' && word[j] <= '9' {
+				j++
+			}
+			s[word[i:j]] = struct{}{}
+			i = j
+		}
+	}
+	return len(s)
+}
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/Solution.java b/solution/1800-1899/1805.Number of Different Integers in a String/Solution.java
@@ -1,17 +1,20 @@
 class Solution {
     public int numDifferentIntegers(String word) {
-        String[] nums = word.split("[a-z]+");
-        Set<String> numSet = new HashSet<>();
-        for (String num : nums) {
-            if ("".equals(num)) {
-                continue;
+        Set<String> s = new HashSet<>();
+        int n = word.length();
+        for (int i = 0; i < n; ++i) {
+            if (Character.isDigit(word.charAt(i))) {
+                while (i < n && word.charAt(i) == '0') {
+                    ++i;
+                }
+                int j = i;
+                while (j < n && Character.isDigit(word.charAt(j))) {
+                    ++j;
+                }
+                s.add(word.substring(i, j));
+                i = j;
             }
-            int j = 0;
-            while (j < num.length() - 1 && num.charAt(j) == '0') {
-                ++j;
-            }
-            numSet.add(num.substring(j));
         }
-        return numSet.size();
+        return s.size();
     }
 }
diff --git a/solution/1800-1899/1805.Number of Different Integers in a String/Solution.py b/solution/1800-1899/1805.Number of Different Integers in a String/Solution.py
@@ -1,7 +1,15 @@
-import re
-
-
 class Solution:
     def numDifferentIntegers(self, word: str) -> int:
-        nums = re.split(r'[a-z]+', word)
-        return len({int(num) for num in nums if num != ''})
+        s = set()
+        i, n = 0, len(word)
+        while i < n:
+            if word[i].isdigit():
+                while i < n and word[i] == '0':
+                    i += 1
+                j = i
+                while j < n and word[j].isdigit():
+                    j += 1
+                s.add(word[i:j])
+                i = j
+            i += 1
+        return len(s)
diff --git a/solution/1800-1899/1807.Evaluate the Bracket Pairs of a String/Solution.py b/solution/1800-1899/1807.Evaluate the Bracket Pairs of a String/Solution.py
@@ -6,7 +6,7 @@ def evaluate(self, s: str, knowledge: List[List[str]]) -> str:
         while i < n:
             if s[i] == '(':
                 j = s.find(')', i + 1)
-                ans.append(d.get(s[i + 1: j], '?'))
+                ans.append(d.get(s[i + 1 : j], '?'))
                 i = j
             else:
                 ans.append(s[i])
diff --git a/solution/2400-2499/2431.Maximize Total Tastiness of Purchased Fruits/Solution.py b/solution/2400-2499/2431.Maximize Total Tastiness of Purchased Fruits/Solution.py
@@ -1,5 +1,7 @@
 class Solution:
-    def maxTastiness(self, price: List[int], tastiness: List[int], maxAmount: int, maxCoupons: int) -> int:
+    def maxTastiness(
+        self, price: List[int], tastiness: List[int], maxAmount: int, maxCoupons: int
+    ) -> int:
         @cache
         def dfs(i, j, k):
             if i == len(price):
@@ -8,8 +10,7 @@ def dfs(i, j, k):
             if j >= price[i]:
                 ans = max(ans, dfs(i + 1, j - price[i], k) + tastiness[i])
             if j >= price[i] // 2 and k:
-                ans = max(
-                    ans, dfs(i + 1, j - price[i] // 2, k - 1) + tastiness[i])
+                ans = max(ans, dfs(i + 1, j - price[i] // 2, k - 1) + tastiness[i])
             return ans
 
         return dfs(0, maxAmount, maxCoupons)

Original file line number	Diff line number	Diff line change
`@@ -141,7 +141,7 @@ public:`
`141`	`141`	`if (c == ')') ++x;`
`142`	`142`	`else if (c == '(') --x;`
`143`	`143`	`ans.push_back(c);`
`144`		`- }`
	`144`	`+ }`
`145`	`145`	`reverse(ans.begin(), ans.end());`
`146`	`146`	`return ans;`
`147`	`147`	`}`