代码如下

dis, time, m = map(int, input().split())
dp = [[0 for i in range(m + 1)] for j in range(time + 1)]
dp[0][0] = 1
mod = 1000000007

for i in range(1, time + 1):
    for j in range(m,-1,-1):
        from_dead = dis + j * 2 - i
        if from_dead <= 0:
            continue
        dp[i][j] += dp[i - 1][j] + dp[i - 1][j - 1]
print(dp[time][m] % mod)
# for line in dp:
#     print(line)

对了一半，但是我看没毛病啊，有没有反例证明一下对错