一、本周周赛总结

• 这周蛮简单的。
• T2 栈的应用。
• T3 离线+大顶堆。
  
  

二、4719. 商品种类

链接: 4719. 商品种类

1. 题目描述

2. 思路分析

就是set去重

3. 代码实现

import sys
from collections import *
from contextlib import redirect_stdout
from itertools import *
from math import sqrt
from array import *
from functools import lru_cache
import heapq
import bisect
import random
import io, os
from bisect import *

RI = lambda: map(int, sys.stdin.buffer.readline().split())
RS = lambda: map(bytes.decode, sys.stdin.buffer.readline().strip().split())
RILST = lambda: list(RI())

MOD = 10 ** 9 + 7


def main():
    n, = RI()
    s = set()
    for _ in range(n):
        p = tuple((RS()))
        s.add(p)

    print(len(s))


if __name__ == '__main__':
    # testcase 2个字段分别是input和output, 前后的回车空格无所谓，会前后strip
    test_cases = (
        (
            """
5
b y
m r
b y
m y
m g
""",
            """
4
"""
        ),
    )
    if os.path.exists('test.test'):
        total_result = 'ok!'
        for i, (in_data, result) in enumerate(test_cases):
            result = result.strip()
            with io.StringIO(in_data.strip()) as buf_in:
                RI = lambda: map(int, buf_in.readline().split())
                RS = lambda: buf_in.readline().strip().split()
                with io.StringIO() as buf_out, redirect_stdout(buf_out):
                    main()
                    output = buf_out.getvalue().strip()
                if output == result:
                    print(f'case{i}, result={result}, output={output}, ---ok!')
                else:
                    print(f'case{i}, result={result}, output={output}, ---WA!---WA!---WA!')
                    total_result = '---WA!---WA!---WA!'
        print('\n', total_result)
    else:
        main()

三、4720. 字符串

链接: 4720. 字符串

1. 题目描述

2. 思路分析

• 题目很贴心的不需要证明，那就按照一种方法直接删除就好了。
• 很显然，题目中需要删除相邻位置；且删完了继续删合并后的相邻位置。
• 明显是栈。

3. 代码实现

import sys
from collections import *
from contextlib import redirect_stdout
from itertools import *
from math import sqrt
from array import *
from functools import lru_cache
import heapq
import bisect
import random
import io, os
from bisect import *

RI = lambda: map(int, sys.stdin.buffer.readline().split())
RS = lambda: map(bytes.decode, sys.stdin.buffer.readline().strip().split())
RILST = lambda: list(RI())
DEBUG = lambda x:sys.stderr.write(x)
MOD = 10 ** 9 + 7


#    	 ms
def solve(s):
    st = []
    for c in s:
        if st and st[-1] == c:
            st.pop()
        else:
            st.append(c)

    print(''.join(st))


def main():
    s, = RS()
    DEBUG(s)
    solve(s)


if __name__ == '__main__':
    # testcase 2个字段分别是input和output
    test_cases = (
        (
            """
aabbcddddefggbbaa
""",
            """
cef
"""
        ),
        (
            """
abcddcef
""",
            """
abef
"""
        ),
        (
            """
abacabaabacabaa
""",
            """
a
"""
        ),
    )
    if os.path.exists('test.test'):
        total_result = 'ok!'
        for i, (in_data, result) in enumerate(test_cases):
            result = result.strip()
            with io.StringIO(in_data.strip()) as buf_in:
                RI = lambda: map(int, buf_in.readline().split())
                RS = lambda: buf_in.readline().strip().split()
                with io.StringIO() as buf_out, redirect_stdout(buf_out):
                    main()
                    output = buf_out.getvalue().strip()
                if output == result:
                    print(f'case{i}, result={result}, output={output}, ---ok!')
                else:
                    print(f'case{i}, result={result}, output={output}, ---WA!---WA!---WA!')
                    total_result = '---WA!---WA!---WA!'
        print('\n', total_result)
    else:
        main()

四、4721. 排队

链接: 4721. 排队

1. 题目描述

2. 思路分析

读了半天题，还以为要树状数组。

• 然后发现离线+堆就可以搞定。
• 把询问排序后，从小到大访问身高，并把访问的下标放到大顶堆中。
• 显然对于当前访问的身高v，如果堆中存在元素，都是比它小的(这里暂时不考虑相等)。
• 那么所有比它小的数，只要下标比它大就是一个不满意，而大顶堆保证了堆顶就是最右的下标，这个下标就是要求的下标。
• 由于py中默认是小顶堆，这里我们取个符号。
• 为了处理相等的情况，我多建立了一个队列，用来暂存身高，只有小于当前值了，才从队列弹出到堆。

3. 代码实现

import sys
from collections import *
from contextlib import redirect_stdout
from itertools import *
from math import sqrt
from array import *
from functools import lru_cache
import heapq
import bisect
import random
import io, os
from bisect import *

RI = lambda: map(int, sys.stdin.buffer.readline().split())
RS = lambda: map(bytes.decode, sys.stdin.buffer.readline().strip().split())
RILST = lambda: list(RI())

MOD = 10 ** 9 + 7


#    	 ms
def solve(n, a):
    h = []
    a = sorted(zip(a, range(n)))
    t = deque()
    ans = [-1] * n
    for v,idx in a:
        while t and a[t[0]]!= v:
            heapq.heappush(h,-t.popleft())
        if h and -h[0]>idx:
            ans[idx] = -h[0]-idx-1
        t.append(idx)


    print(' '.join(map(str,ans)))


def main():
    n, = RI()
    a = RILST()
    solve(n, a)


if __name__ == '__main__':
    # testcase 2个字段分别是input和output
    test_cases = (
        (
            """
6
10 8 5 3 50 45
""",
            """
2 1 0 -1 0 -1
"""
        ),
        (
            """
7
10 4 6 3 2 8 15
""",
            """
4 2 1 0 -1 -1 -1 
"""
        ),
        (
            """
5
10 3 1 10 11
""",
            """
1 0 -1 -1 -1 
"""
        ),
    )
    if os.path.exists('test.test'):
        total_result = 'ok!'
        for i, (in_data, result) in enumerate(test_cases):
            result = result.strip()
            with io.StringIO(in_data.strip()) as buf_in:
                RI = lambda: map(int, buf_in.readline().split())
                RS = lambda: map(bytes.decode, buf_in.readline().strip().split())
                with io.StringIO() as buf_out, redirect_stdout(buf_out):
                    main()
                    output = buf_out.getvalue().strip()
                if output == result:
                    print(f'case{i}, result={result}, output={output}, ---ok!')
                else:
                    print(f'case{i}, result={result}, output={output}, ---WA!---WA!---WA!')
                    total_result = '---WA!---WA!---WA!'
        print('\n', total_result)
    else:
        main()

六、参考链接

• 无