60分求助！！！ #3 #7

levy3304 @ 2023-08-24 21:31:09

#include<bits/stdc++.h>
#define ll long long
using namespace std; 
bool vis[21][21][21];
ll v[21][21][21];
ll w(int a,int b,int c){
    if(a<=0||b<=0||c<=0) return 1;
    else if(vis[a][b][c]) return v[a][b][c];
    else if(a<b&&b<c) v[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
    else v[a][b][c]=w(a-1,b,c)+w(a-1,b-1,c)+w(a-1,b,c-1)-w(a-1,b-1,c-1);
    vis[a][b][c]=true;
    return v[a][b][c];
}
int main(){
    ll a=0,b=0,c=0;
    memset(vis,false,sizeof(vis));
    while(1){
        cin>>a>>b>>c
        if(a==-1&&b==-1&&c==-1) break;
        ll ina=a,inb=b,inc=c;
        if(a>20||b>20||c>20){
            a=20;
            b=20;
            c=20;
        }
        cout<<"w("<<ina<<", "<<inb<<", "<<inc<<")"<<" = "<<w(a,b,c)<<endl;
    }
    return 0;
}

by zhouzihang1 @ 2023-08-24 21:36:24

while(1){
        cin>>a>>b>>c
        if(a==-1&&b==-1&&c==-1) break;
        ll ina=a,inb=b,inc=c;
        if(a>20||b>20||c>20){
            a=20;
            b=20;
            c=20;
        }
        cout<<"w("<<ina<<", "<<inb<<", "<<inc<<")"<<" = "<<w(a,b,c)<<endl;
    }

给一组hack

-1 10 20

正确答案：1

你的答案：1048576

by zhouzihang1 @ 2023-08-24 21:37:15

先判断有没有<=0的，在判断有没有>20的

by zhouzihang1 @ 2023-08-24 21:38:08

@levy2011

by levy3304 @ 2023-08-24 22:06:00

@zhouzihang1 改完了，变成#1 #2 WA

#include<bits/stdc++.h>
#define ll long long
using namespace std; 
bool vis[21][21][21];
ll v[21][21][21];
ll w(int a,int b,int c){
    if(a<=0||b<=0||c<=0) return 1;
    if(a>20||b>20||c>20) return w(20,20,20);
    else if(vis[a][b][c]) return v[a][b][c];
    else if(a<b&&b<c) v[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
    else v[a][b][c]=w(a-1,b,c)+w(a-1,b-1,c)+w(a-1,b,c-1)-w(a-1,b-1,c-1);
    vis[a][b][c]=true;
    return v[a][b][c];
}
int main(){
    ll a=0,b=0,c=0;
    memset(vis,false,sizeof(vis));
    while(1){
        cin>>a>>b>>c;
        if(a==-1&&b==-1&&c==-1) break;
        cout<<"w("<<a<<", "<<b<<", "<<c<<")"<<" = "<<w(a,b,c)<<endl;
    }
    return 0;
}

by levy3304 @ 2023-08-24 22:06:57

求指点

by zhouzihang1 @ 2023-08-25 07:26:56

else if(vis[a][b][c]) return v[a][b][c];

改成

else if(v[a][b][c]) return v[a][b][c];

试试？

by levy3304 @ 2023-08-25 09:26:57

@zhouzihang1 还是#1 #2 WA

by levy3304 @ 2023-08-25 10:24:45

AC了，感谢大佬指点！