题解 | 二维斐波那契数列

package main

import (
	"fmt"
)
const mod=1e9+7
func main() {
	var n, m int
	fmt.Scan(&n, &m)
	a := make([][]int, n+1)
	for i := range a {
		a[i] = make([]int, m+1)
	}
	for i := 1; i <= n; i++ {
		a[i][1] = 1
	}
	for j := 1; j <= m; j++ {
		a[1][j] = 1
	}
	for i := 2; i <= n; i++ {
		for j := 2; j <= m; j++ {
			a[i][j] = (a[i-1][j] + a[i][j-1])%mod
		}
	}
	fmt.Print(a[n][m])
}