feat: add solutions to lc problem: No.1297

Author: yanglbme

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/README.md

@@ -9,10 +9,10 @@ public int maxFreq(String s, int maxLetters, int minSize, int maxSize) {
                 ss.add(t.charAt(j));
             }
             if (ss.size() <= maxLetters) {
-                cnt.put(t, cnt.getOrDefault(t, 0) + 1);
+                cnt.merge(t, 1, Integer::sum);
                 ans = Math.max(ans, cnt.get(t));
             }
         }
         return ans;
     }
-}
+}

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/README_EN.md

@@ -0,0 +1,31 @@
+use std::collections::{HashMap, HashSet};
+
+impl Solution {
+    pub fn max_freq(s: String, max_letters: i32, min_size: i32, _max_size: i32) -> i32 {
+        let n = s.len();
+        let m = min_size as usize;
+        let max_letters = max_letters as usize;
+        let bytes = s.as_bytes();
+        let mut cnt: HashMap<&[u8], i32> = HashMap::new();
+        let mut ans = 0;
+
+        for i in 0..=n - m {
+            let t = &bytes[i..i + m];
+
+            let mut set = HashSet::new();
+            for &c in t {
+                set.insert(c);
+                if set.len() > max_letters {
+                    break;
+                }
+            }
+            if set.len() <= max_letters {
+                let v = cnt.entry(t).or_insert(0);
+                *v += 1;
+                ans = ans.max(*v);
+            }
+        }
+
+        ans
+    }
+}

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution.java

@@ -0,0 +1,54 @@
+class Hashing {
+public:
+    vector<long long> p, h;
+    long long mod;
+
+    Hashing(const string& word)
+        : Hashing(word, 13331, 998244353) {}
+
+    Hashing(const string& word, long long base, long long mod)
+        : mod(mod) {
+        int n = word.size();
+        p.assign(n + 1, 1);
+        h.assign(n + 1, 0);
+        for (int i = 1; i <= n; i++) {
+            p[i] = p[i - 1] * base % mod;
+            h[i] = (h[i - 1] * base + word[i - 1]) % mod;
+        }
+    }
+
+    long long query(int l, int r) {
+        return (h[r] - h[l - 1] * p[r - l + 1] % mod + mod) % mod;
+    }
+};
+
+class Solution {
+public:
+    int maxFreq(string s, int maxLetters, int minSize, int maxSize) {
+        int n = s.size();
+        Hashing hashing(s);
+        vector<int> freq(256, 0);
+        int k = 0;
+        int ans = 0;
+        unordered_map<long long, int> cnt;
+
+        for (int i = 1; i <= n; i++) {
+            if (++freq[s[i - 1]] == 1) {
+                k++;
+            }
+
+            if (i >= minSize) {
+                if (k <= maxLetters) {
+                    long long x = hashing.query(i - minSize + 1, i);
+                    ans = max(ans, ++cnt[x]);
+                }
+                int j = i - minSize;
+                if (--freq[s[j]] == 0) {
+                    k--;
+                }
+            }
+        }
+
+        return ans;
+    }
+};

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution.rs

@@ -0,0 +1,60 @@
+func maxFreq(s string, maxLetters int, minSize int, maxSize int) int {
+	n := len(s)
+	hashing := NewHashing(s)
+	freq := make([]int, 256)
+	k := 0
+	ans := 0
+	cnt := make(map[uint64]int)
+
+	for i := 1; i <= n; i++ {
+		c := s[i-1]
+		freq[c]++
+		if freq[c] == 1 {
+			k++
+		}
+
+		if i >= minSize {
+			if k <= maxLetters {
+				x := hashing.Query(i-minSize+1, i)
+				cnt[x]++
+				if cnt[x] > ans {
+					ans = cnt[x]
+				}
+			}
+			j := i - minSize
+			c2 := s[j]
+			freq[c2]--
+			if freq[c2] == 0 {
+				k--
+			}
+		}
+	}
+
+	return ans
+}
+
+type Hashing struct {
+	p, h []uint64
+	mod  uint64
+	base uint64
+}
+
+func NewHashing(word string) *Hashing {
+	return NewHashingWithBase(word, 13331, 998244353)
+}
+
+func NewHashingWithBase(word string, base uint64, mod uint64) *Hashing {
+	n := len(word)
+	p := make([]uint64, n+1)
+	h := make([]uint64, n+1)
+	p[0] = 1
+	for i := 1; i <= n; i++ {
+		p[i] = p[i-1] * base % mod
+		h[i] = (h[i-1]*base + uint64(word[i-1])) % mod
+	}
+	return &Hashing{p, h, mod, base}
+}
+
+func (hs *Hashing) Query(l, r int) uint64 {
+	return (hs.h[r] + hs.mod - hs.h[l-1]*hs.p[r-l+1]%hs.mod) % hs.mod
+}

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution2.cpp

@@ -0,0 +1,55 @@
+class Hashing {
+    private final long[] p;
+    private final long[] h;
+    private final long mod;
+
+    public Hashing(String word) {
+        this(word, 13331, 998244353);
+    }
+
+    public Hashing(String word, long base, int mod) {
+        int n = word.length();
+        p = new long[n + 1];
+        h = new long[n + 1];
+        p[0] = 1;
+        this.mod = mod;
+        for (int i = 1; i <= n; i++) {
+            p[i] = p[i - 1] * base % mod;
+            h[i] = (h[i - 1] * base + word.charAt(i - 1)) % mod;
+        }
+    }
+
+    public long query(int l, int r) {
+        return (h[r] - h[l - 1] * p[r - l + 1] % mod + mod) % mod;
+    }
+}
+
+class Solution {
+    public int maxFreq(String s, int maxLetters, int minSize, int maxSize) {
+        int n = s.length();
+        Hashing hashing = new Hashing(s);
+        int[] freq = new int[256];
+        int k = 0;
+        int ans = 0;
+        Map<Long, Integer> cnt = new HashMap<>();
+
+        for (int i = 1; i <= n; i++) {
+            if (++freq[s.charAt(i - 1)] == 1) {
+                k++;
+            }
+
+            if (i >= minSize) {
+                if (k <= maxLetters) {
+                    long x = hashing.query(i - minSize + 1, i);
+                    ans = Math.max(ans, cnt.merge(x, 1, Integer::sum));
+                }
+                int j = i - minSize;
+                if (--freq[s.charAt(j)] == 0) {
+                    k--;
+                }
+            }
+        }
+
+        return ans;
+    }
+}

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution2.go

@@ -0,0 +1,37 @@
+class Hashing:
+    __slots__ = ["mod", "h", "p"]
+
+    def __init__(
+        self, s: Union[str, List[str]], base: int = 13331, mod: int = 998244353
+    ):
+        self.mod = mod
+        self.h = [0] * (len(s) + 1)
+        self.p = [1] * (len(s) + 1)
+        for i in range(1, len(s) + 1):
+            self.h[i] = (self.h[i - 1] * base + ord(s[i - 1])) % mod
+            self.p[i] = (self.p[i - 1] * base) % mod
+
+    def query(self, l: int, r: int) -> int:
+        return (self.h[r] - self.h[l - 1] * self.p[r - l + 1]) % self.mod
+
+
+class Solution:
+    def maxFreq(self, s: str, maxLetters: int, minSize: int, maxSize: int) -> int:
+        freq = Counter()
+        hashing = Hashing(s)
+        cnt = Counter()
+        ans = k = 0
+        for i, c in enumerate(s, 1):
+            freq[c] += 1
+            if freq[c] == 1:
+                k += 1
+            if i >= minSize:
+                if k <= maxLetters:
+                    x = hashing.query(i - minSize + 1, i)
+                    cnt[x] += 1
+                    ans = max(ans, cnt[x])
+                j = i - minSize
+                freq[s[j]] -= 1
+                if freq[s[j]] == 0:
+                    k -= 1
+        return ans

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution2.java

@@ -0,0 +1,67 @@
+impl Solution {
+    pub fn max_freq(s: String, max_letters: i32, min_size: i32, _max_size: i32) -> i32 {
+        let n = s.len();
+        let bytes = s.as_bytes();
+        let hashing = Hashing::new(bytes.to_vec());
+        let mut freq = [0i32; 256];
+        let mut k = 0;
+        let mut ans = 0;
+        let mut cnt: std::collections::HashMap<u64, i32> = std::collections::HashMap::new();
+
+        for i in 1..=n {
+            let c = bytes[i - 1] as usize;
+            freq[c] += 1;
+            if freq[c] == 1 {
+                k += 1;
+            }
+
+            if i as i32 >= min_size {
+                if k <= max_letters {
+                    let x = hashing.query(i - min_size as usize, i - 1);
+                    let v = cnt.entry(x).and_modify(|v| *v += 1).or_insert(1);
+                    ans = ans.max(*v);
+                }
+                let j = i - min_size as usize;
+                let c2 = bytes[j] as usize;
+                freq[c2] -= 1;
+                if freq[c2] == 0 {
+                    k -= 1;
+                }
+            }
+        }
+
+        ans
+    }
+}
+
+struct Hashing {
+    p: Vec<u64>,
+    h: Vec<u64>,
+    base: u64,
+    modv: u64,
+}
+
+impl Hashing {
+    fn new(s: Vec<u8>) -> Self {
+        Self::with_params(s, 13331, 998244353)
+    }
+
+    fn with_params(s: Vec<u8>, base: u64, modv: u64) -> Self {
+        let n = s.len();
+        let mut p = vec![0u64; n + 1];
+        let mut h = vec![0u64; n + 1];
+        p[0] = 1;
+        for i in 1..=n {
+            p[i] = p[i - 1].wrapping_mul(base) % modv;
+            h[i] = (h[i - 1].wrapping_mul(base) + s[i - 1] as u64) % modv;
+        }
+        Self { p, h, base, modv }
+    }
+
+    fn query(&self, l: usize, r: usize) -> u64 {
+        let mut res =
+            self.h[r + 1] + self.modv - (self.h[l] * self.p[r - l + 1] % self.modv);
+        res %= self.modv;
+        res
+    }
+}

solution/1200-1299/1297.Maximum Number of Occurrences of a Substring/Solution2.py

@@ -0,0 +1,52 @@
+class Hashing {
+    private p: bigint[];
+    private h: bigint[];
+    private mod: bigint;
+
+    constructor(s: string, base: bigint = 13331n, mod: bigint = 998244353n) {
+        const n = s.length;
+        this.mod = mod;
+        this.p = new Array<bigint>(n + 1).fill(1n);
+        this.h = new Array<bigint>(n + 1).fill(0n);
+        for (let i = 1; i <= n; i++) {
+            this.p[i] = (this.p[i - 1] * base) % mod;
+            this.h[i] = (this.h[i - 1] * base + BigInt(s.charCodeAt(i - 1))) % mod;
+        }
+    }
+
+    query(l: number, r: number): bigint {
+        return (this.h[r] - ((this.h[l - 1] * this.p[r - l + 1]) % this.mod) + this.mod) % this.mod;
+    }
+}
+
+function maxFreq(s: string, maxLetters: number, minSize: number, maxSize: number): number {
+    const n = s.length;
+    const hashing = new Hashing(s);
+    const freq = new Array<number>(256).fill(0);
+    let k = 0;
+    let ans = 0;
+    const cnt = new Map<bigint, number>();
+
+    for (let i = 1; i <= n; i++) {
+        const c = s.charCodeAt(i - 1);
+        if (++freq[c] === 1) {
+            k++;
+        }
+
+        if (i >= minSize) {
+            if (k <= maxLetters) {
+                const x = hashing.query(i - minSize + 1, i);
+                const v = (cnt.get(x) || 0) + 1;
+                cnt.set(x, v);
+                ans = Math.max(ans, v);
+            }
+            const j = i - minSize;
+            const c2 = s.charCodeAt(j);
+            if (--freq[c2] === 0) {
+                k--;
+            }
+        }
+    }
+
+    return ans;
+}