算法基础模板

基础算法模板

tire树

#版本一：
class Tire:
    def __init__(self):
        self.tire = [0, {}]
    def insert(self, word):
        p = self.tire
        for char in word:
            if char not in p[1]:
                p[1][char] = [0, {}]
            p = p[1][char]
        p[0] += 1
    def query(self, word):
        p = self.tire
        for char in word:
            if char not in p[1]:
                return 0
            else:
                p = p[1][char]
        return p[0]
if __name__ == "__main__":
    n = int(input())
    T = Tire()
    for _ in range(n):
        op, word = input().split()
        if op == "I":
            T.insert(word)
        else:
            print(T.query(word))
#版本二
N = 10 ** 5 + 10
n = int(input())
tire = [[0 for _ in range(27)] for _ in range(N)]
cnt = [0] * N
idx = 0

def insert(word):
    global idx
    p = 0
    for char in word:
        u = ord(char) - ord('a')
        if tire[p][u] == 0:
            idx += 1
            tire[p][u] = idx
        p = tire[p][u]
    cnt[p] += 1

def query(word):
    p = 0
    for char in word:
        u = ord(char) - ord('a')
        if tire[p][u] == 0:
            return 0
        else:
            p = tire[p][u]
    return cnt[p]

for _ in range(n):
    op, word = input().split()
    if op ==  "I":
        insert(word)
    else:
        print(query(word))

KMP

n = int(input())
s = " " + input()
m = int(input())
t = " " + input()

ne = [0] * 100010

j = 0
for i in range(2, n + 1):
    while j and s[i] != s[j + 1]: 
        j = ne[j]
    if s[i] == s[j + 1]:
        j += 1
    ne[i] = j

j = 0

for i in range(1, m + 1):
    while j and t[i] != s[j + 1]:
        j = ne[j]
    if t[i] == s[j + 1]:
        j += 1
    if j == n:
        print(i - j, end =' ')
        j = ne[j]

单调栈

n = input()
nums = list(map(int, input().split()))

deq = []

for i in range(len(nums)):
    while deq and deq[-1] >= nums[i]:
        deq.pop()
    if len(deq) != 0:
        print(deq[-1], end = " ")
    else:
        print(-1, end = " ")
    
    deq.append(nums[i])