题解 | 二维斐波那契数列

import sys
n,m=map(int,sys.stdin.readline().split())
a=[[0] * (m + 1) for _ in range(n + 1)]
for i in range(1,n+1):
    a[i][1]=1
for j in range(1,m+1):
    a[1][j]=1
for i in range(2,n+1):
    for j in range(2,m+1):
        a[i][j]=a[i-1][j]+a[i][j-1]
print(a[n][m]%(10**9+7))