Submission #4240896

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Source Code Expand

def solve(s):
    """
    桁DP
    dp[keta][isBaned][isEqual]
    """
    length = len(s)
    dp = [[[0] * 2 for _ in range(2)] for _ in range(length)]
    dp[-1][0][1] = 1
    for i in range(length):
        num = int(s[i])
        if num <= 3:
            dp[i][0][0] = dp[i - 1][0][0] * 8 + dp[i - 1][0][1] * num
            dp[i][0][1] = dp[i - 1][0][1]
            dp[i][1][0] = dp[i - 1][0][0] * 2 + dp[i - 1][1][0] * 10 + dp[i - 1][1][1] * num
            dp[i][1][1] = dp[i - 1][1][1]
        elif num == 4:
            dp[i][0][0] = dp[i - 1][0][0] * 8 + dp[i - 1][0][1] * num
            dp[i][0][1] = 0
            dp[i][1][0] = dp[i - 1][0][0] * 2 + dp[i - 1][1][0] * 10 + dp[i - 1][1][1] * num
            dp[i][1][1] = 1
        elif num <= 8:
            dp[i][0][0] = dp[i - 1][0][0] * 8 + dp[i - 1][0][1] * (num - 1)
            dp[i][0][1] = dp[i - 1][0][1]
            dp[i][1][0] = dp[i - 1][0][0] * 2 + dp[i - 1][0][1] + dp[i - 1][1][0] * 10 + dp[i - 1][1][1] * num
            dp[i][1][1] = dp[i - 1][1][1]
        elif num == 9:
            dp[i][0][0] = dp[i - 1][0][0] * 8 + dp[i - 1][0][1] * (num - 1)
            dp[i][0][1] = 0
            dp[i][1][0] = dp[i - 1][0][0] * 2 + dp[i - 1][0][1] + dp[i - 1][1][0] * 10 + dp[i - 1][1][1] * num
            dp[i][1][1] = 1
    return dp[length - 1][1][0] + dp[length - 1][1][1]

a, b = input().split()
print(solve(b) - solve(str(int(a) - 1)))

Submission Info

Judge Result