結果

問題 No.1526 Sum of Mex 2
ユーザー gew1fw
提出日時 2025-06-12 15:14:36
言語 PyPy3
(7.3.15)
結果
TLE  
実行時間 -
コード長 2,752 bytes
コンパイル時間 217 ms
コンパイル使用メモリ 82,452 KB
実行使用メモリ 116,004 KB
最終ジャッジ日時 2025-06-12 15:14:49
合計ジャッジ時間 8,296 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 30 TLE * 1 -- * 1
権限があれば一括ダウンロードができます

ソースコード

diff # 

import bisect

def main():
    import sys
    input = sys.stdin.read().split()
    n = int(input[0])
    A = list(map(int, input[1:n+1]))
    
    # Compute the mex of the entire array
    present = set()
    mex = 1
    for num in A:
        present.add(num)
        while mex in present:
            mex += 1
    
    # Precompute the positions for each number
    from collections import defaultdict
    pos = defaultdict(list)
    for idx, num in enumerate(A):
        pos[num].append(idx)
    
    total = 0
    
    for x in range(1, mex + 1):
        # Get all positions of x, sorted
        x_pos = pos.get(x, [])
        regions = []
        prev = -1
        for p in x_pos:
            if prev + 1 <= p - 1:
                regions.append((prev + 1, p - 1))
            prev = p
        if prev != n - 1:
            regions.append((prev + 1, n - 1))
        
        # Check if x-1 is present in the entire array
        required = set(range(1, x))
        if x > 1 and any(y not in pos or len(pos[y]) == 0 for y in required):
            continue
        
        cnt = 0
        for (s, e) in regions:
            # Check if this region contains all required elements
            valid = True
            if x > 1:
                for y in required:
                    ys = pos[y]
                    idx = bisect.bisect_left(ys, s)
                    if idx >= len(ys) or ys[idx] > e:
                        valid = False
                        break
            if not valid:
                continue
            
            # Now compute the number of intervals in [s, e] that contain all required elements
            # Using sliding window
            if x == 1:
                # All intervals in this region are valid
                L = e - s + 1
                cnt += L * (L + 1) // 2
                continue
            
            freq = {}
            required_count = len(required)
            current_count = 0
            res = 0
            left = s
            for right in range(s, e + 1):
                num = A[right]
                if num in required:
                    if num not in freq or freq[num] == 0:
                        current_count += 1
                    freq[num] = freq.get(num, 0) + 1
                
                while current_count == required_count:
                    res += e - right + 1
                    # Move left
                    left_num = A[left]
                    if left_num in required:
                        freq[left_num] -= 1
                        if freq[left_num] == 0:
                            current_count -= 1
                    left += 1
            cnt += res
        total += x * cnt
    print(total)

if __name__ == "__main__":
    main()
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