https://www.cnblogs.com/Kobe10/p/6357526.html
#include <iostream>
using namespace std;
//dp[i][j] = dp[i-1][j] + dp[i][j-1];
int get_steps_num(int* a, int m; int n) {
if (a==nullptr || m<=0 || n<=0) {
return -1;
}
int dp[m][n];
for (int i=0; i<m; i++)
for(int j=0; j<n; j++) {
d[i][j] = 1;
}
if (m == 1) {
return 1;
}
if (n == 1) {
return 1;
}
for (int i=1; i<m; i++)
for(int j=1; j<n; j++) {
dp[i][j] = dp[i-1][j] + dp[i][j-1];
}
return dp[m-1][n-1];
}
int main() {
//int a;
//cin >> a;
int res = get_steps_num();
}