题解(记得开long long)

#include<iostream>
using namespace std;
long long dp[105][105];
int main(){
    long long n,m;
    cin>>n>>m;
    for(long long i=1;i<=n;i++){
        for(long long j=1;j<=m;j++){
            if(i==1||j==1){
                dp[i][j]=1;
                continue;
            }
            dp[i][j]=dp[i-1][j]+dp[i][j-1];
        }
    }
    cout<<dp[n][m]<<endl;
}