Submission #1166401

#	Time	Username	Problem	Language	Result	Execution time	Memory
1166401		son2008	Paths (BOI18_paths)	C++20	53 / 100	117 ms	33988 KiB

paths

#include<bits/stdc++.h>
using namespace std;
#define task "task"
#define ii pair<int,int>
#define fi first
#define se second
//#define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define base 29
#define eps 1e-8
int dx[]= {0LL,0LL,1,-1,1,1,-1,-1};
int dy[]= {1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=1e5+1;
const int mod=1e9+7;
int n,a[maxn],m,k;
ll dp[maxn][35];
vector<int>e[maxn];
void init()
{
    cin>>n>>m>>k;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        a[i]--;
        dp[i][1<<a[i]]=1;
    }
    for(int i=1;i<=m;i++)
    {
        int u,v;
        cin>>u>>v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
}
void process()
{
    ll ans=0;
    for(int mask=0;mask<(1<<k);mask++)
    {
        for(int u=1;u<=n;u++)
        {
            for(int v:e[u])
            {
                if(mask&(1<<a[v]))continue;
                dp[v][mask^(1<<a[v])]+=dp[u][mask];
            }
            ans+=dp[u][mask];
        }
    }
    cout<<ans-n;
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    init();
    process();
    cerr <<endl<< "TIME : " << clock() * 0.001 << "s" << endl ;
}

Compilation message (stderr)

paths.cpp: In function 'int main()':
paths.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
paths.cpp:65:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 23 / 23
• Subtask 2: 0 / 20
• Subtask 3: 0 / 27
• Subtask 4: 30 / 30