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feat: add solutions to lcof2 problems: No.014,015 (doocs#1401)
 * No.014.字符串中的变位词 * No.015.字符串中的所有变位词
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12 files changed

+996
-359
lines changed

12 files changed

+996
-359
lines changed

‎lcof2/剑指 Offer II 014. 字符串中的变位词/README.md

Lines changed: 308 additions & 86 deletions
Large diffs are not rendered by default.

‎lcof2/剑指 Offer II 014. 字符串中的变位词/Solution.cpp

Lines changed: 44 additions & 45 deletions
Original file line numberDiff line numberDiff line change
@@ -1,46 +1,45 @@
1-
class Solution {
2-
public:
3-
bool checkInclusion(string s1, string s2) {
4-
5-
int len1 = s1.size();
6-
int len2 = s2.size();
7-
8-
if (len2 < len1) {
9-
return false;
10-
}
11-
12-
int count[30] = {0};
13-
14-
for (int i = 0; i < len1; ++i) {
15-
++count[s1[i] - 'a'];
16-
--count[s2[i] - 'a'];
17-
}
18-
19-
int l = 0;
20-
int r = len1 - 1;
21-
22-
while (r < len2) {
23-
24-
bool flag = true;
25-
26-
for (int i : count) {
27-
if (i != 0) {
28-
flag = false;
29-
}
30-
}
31-
32-
if (flag) {
33-
return true;
34-
}
35-
36-
if (r + 1 >= len2) {
37-
break;
38-
}
39-
40-
++count[s2[l++] - 'a'];
41-
--count[s2[++r] - 'a'];
42-
}
43-
44-
return false;
45-
}
1+
class Solution {
2+
public:
3+
bool checkInclusion(string s1, string s2) {
4+
int m = s1.size(), n = s2.size();
5+
if (m > n) {
6+
return false;
7+
}
8+
vector<int> cnt(26);
9+
for (int i = 0; i < m; ++i) {
10+
--cnt[s1[i] - 'a'];
11+
++cnt[s2[i] - 'a'];
12+
}
13+
int diff = 0;
14+
for (int x : cnt) {
15+
if (x != 0) {
16+
++diff;
17+
}
18+
}
19+
if (diff == 0) {
20+
return true;
21+
}
22+
for (int i = m; i < n; ++i) {
23+
int a = s2[i - m] - 'a';
24+
int b = s2[i] - 'a';
25+
if (cnt[a] == 0) {
26+
++diff;
27+
}
28+
--cnt[a];
29+
if (cnt[a] == 0) {
30+
--diff;
31+
}
32+
if (cnt[b] == 0) {
33+
++diff;
34+
}
35+
++cnt[b];
36+
if (cnt[b] == 0) {
37+
--diff;
38+
}
39+
if (diff == 0) {
40+
return true;
41+
}
42+
}
43+
return false;
44+
}
4645
};

‎lcof2/剑指 Offer II 014. 字符串中的变位词/Solution.go

Lines changed: 30 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -1,31 +1,41 @@
11
func checkInclusion(s1 string, s2 string) bool {
2-
n1, n2 := len(s1), len(s2)
3-
if n1 > n2 {
2+
m, n := len(s1), len(s2)
3+
if m > n {
44
return false
55
}
6-
window := make([]int, 26)
7-
for i := 0; i < n1; i++ {
8-
window[s1[i]-'a']++
9-
window[s2[i]-'a']--
6+
cnt := [26]int{}
7+
for i := 0; i < m; i++ {
8+
cnt[s1[i]-'a']--
9+
cnt[s2[i]-'a']++
1010
}
11-
if check(window) {
11+
diff := 0
12+
for _, x := range cnt {
13+
if x != 0 {
14+
diff++
15+
}
16+
}
17+
if diff == 0 {
1218
return true
1319
}
14-
for i := n1; i < n2; i++ {
15-
window[s2[i]-'a']--
16-
window[s2[i-n1]-'a']++
17-
if check(window) {
20+
for i := m; i < n; i++ {
21+
a, b := s2[i-m]-'a', s2[i]-'a'
22+
if cnt[a] == 0 {
23+
diff++
24+
}
25+
cnt[a]--
26+
if cnt[a] == 0 {
27+
diff--
28+
}
29+
if cnt[b] == 0 {
30+
diff++
31+
}
32+
cnt[b]++
33+
if cnt[b] == 0 {
34+
diff--
35+
}
36+
if diff == 0 {
1837
return true
1938
}
2039
}
2140
return false
22-
}
23-
24-
func check(window []int) bool {
25-
for _, cnt := range window {
26-
if cnt != 0 {
27-
return false
28-
}
29-
}
30-
return true
3141
}

‎lcof2/剑指 Offer II 014. 字符串中的变位词/Solution.java

Lines changed: 45 additions & 28 deletions
Original file line numberDiff line numberDiff line change
@@ -1,28 +1,45 @@
1-
class Solution {
2-
public boolean checkInclusion(String s1, String s2) {
3-
int n1 = s1.length(), n2 = s2.length();
4-
if (n1 > n2) {
5-
return false;
6-
}
7-
int[] window = new int[26];
8-
for (int i = 0; i < n1; i++) {
9-
window[s1.charAt(i) - 'a']++;
10-
window[s2.charAt(i) - 'a']--;
11-
}
12-
if (check(window)) {
13-
return true;
14-
}
15-
for (int i = n1; i < n2; i++) {
16-
window[s2.charAt(i) - 'a']--;
17-
window[s2.charAt(i - n1) - 'a']++;
18-
if (check(window)) {
19-
return true;
20-
}
21-
}
22-
return false;
23-
}
24-
25-
private boolean check(int[] window) {
26-
return Arrays.stream(window).allMatch(cnt -> cnt == 0);
27-
}
28-
}
1+
class Solution {
2+
public boolean checkInclusion(String s1, String s2) {
3+
int m = s1.length();
4+
int n = s2.length();
5+
if (m > n) {
6+
return false;
7+
}
8+
int[] cnt = new int[26];
9+
for (int i = 0; i < m; ++i) {
10+
--cnt[s1.charAt(i) - 'a'];
11+
++cnt[s2.charAt(i) - 'a'];
12+
}
13+
int diff = 0;
14+
for (int x : cnt) {
15+
if (x != 0) {
16+
++diff;
17+
}
18+
}
19+
if (diff == 0) {
20+
return true;
21+
}
22+
for (int i = m; i < n; ++i) {
23+
int a = s2.charAt(i - m) - 'a';
24+
int b = s2.charAt(i) - 'a';
25+
if (cnt[a] == 0) {
26+
++diff;
27+
}
28+
--cnt[a];
29+
if (cnt[a] == 0) {
30+
--diff;
31+
}
32+
if (cnt[b] == 0) {
33+
++diff;
34+
}
35+
++cnt[b];
36+
if (cnt[b] == 0) {
37+
--diff;
38+
}
39+
if (diff == 0) {
40+
return true;
41+
}
42+
}
43+
return false;
44+
}
45+
}

‎lcof2/剑指 Offer II 014. 字符串中的变位词/Solution.py

Lines changed: 27 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -1,20 +1,27 @@
1-
class Solution:
2-
def checkInclusion(self, s1: str, s2: str) -> bool:
3-
n1, n2 = len(s1), len(s2)
4-
if n1 > n2:
5-
return False
6-
window = [0 for _ in range(26)]
7-
for i in range(n1):
8-
window[ord(s1[i]) - ord('a')] += 1
9-
window[ord(s2[i]) - ord('a')] -= 1
10-
if self.check(window):
11-
return True
12-
for i in range(n1, n2):
13-
window[ord(s2[i]) - ord('a')] -= 1
14-
window[ord(s2[i - n1]) - ord('a')] += 1
15-
if self.check(window):
16-
return True
17-
return False
18-
19-
def check(self, window: List[int]) -> bool:
20-
return all([cnt == 0 for cnt in window])
1+
class Solution:
2+
def checkInclusion(self, s1: str, s2: str) -> bool:
3+
m, n = len(s1), len(s2)
4+
if m > n:
5+
return False
6+
cnt = Counter()
7+
for a, b in zip(s1, s2):
8+
cnt[a] -= 1
9+
cnt[b] += 1
10+
diff = sum(x != 0 for x in cnt.values())
11+
if diff == 0:
12+
return True
13+
for i in range(m, n):
14+
a, b = s2[i - m], s2[i]
15+
if cnt[a] == 0:
16+
diff += 1
17+
cnt[a] -= 1
18+
if cnt[a] == 0:
19+
diff -= 1
20+
if cnt[b] == 0:
21+
diff += 1
22+
cnt[b] += 1
23+
if cnt[b] == 0:
24+
diff -= 1
25+
if diff == 0:
26+
return True
27+
return False

‎lcof2/剑指 Offer II 014. 字符串中的变位词/Solution.ts

Lines changed: 41 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,41 @@
1+
function checkInclusion(s1: string, s2: string): boolean {
2+
const m = s1.length;
3+
const n = s2.length;
4+
if (m > n) {
5+
return false;
6+
}
7+
const cnt: number[] = new Array(26).fill(0);
8+
for (let i = 0; i < m; ++i) {
9+
--cnt[s1[i].charCodeAt(0) - 'a'.charCodeAt(0)];
10+
++cnt[s2[i].charCodeAt(0) - 'a'.charCodeAt(0)];
11+
}
12+
let diff = 0;
13+
for (const x of cnt) {
14+
if (x !== 0) {
15+
++diff;
16+
}
17+
}
18+
if (diff === 0) {
19+
return true;
20+
}
21+
for (let i = m; i < n; ++i) {
22+
const a = s2[i - m].charCodeAt(0) - 'a'.charCodeAt(0);
23+
const b = s2[i].charCodeAt(0) - 'a'.charCodeAt(0);
24+
if (cnt[a] === 0) {
25+
++diff;
26+
}
27+
if (--cnt[a] === 0) {
28+
--diff;
29+
}
30+
if (cnt[b] === 0) {
31+
++diff;
32+
}
33+
if (++cnt[b] === 0) {
34+
--diff;
35+
}
36+
if (diff === 0) {
37+
return true;
38+
}
39+
}
40+
return false;
41+
}

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