Submission #978012

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Source Code Expand

a, b = map(int, input().split())

def f(n):
    dp = [[0] * 2 for i in range(len(n)+1)]
    dp[0][1] = 1
    for i in range(len(n)):
        for j in range(2):
            if(j == 0):
                dp[i+1][j] += dp[i][j] * 8
            if(j == 1):
                for k in range(int(n[i])+1):
                    if k == 4 or k == 9: continue
                    if k != int(n[i]):
                        dp[i+1][0] += dp[i][j]
                    else:
                        dp[i+1][1] += dp[i][j]
    return sum(dp[len(n)])

print(b-a+1-f(str(b))+f(str(a-1)))

Submission Info

Judge Result