Submission #213442

#	Time	Username	Problem	Language	Result	Execution time	Memory
213442		MKopchev	Paths (BOI18_paths)	C++14	100 / 100	420 ms	54392 KiB

paths

#include<bits/stdc++.h>
using namespace std;
const int nmax=3e5+42;
long long dp[32][nmax];

int colour[nmax];
vector<int> adj[nmax];

int n,m,k;

long long rec(int remain,int pos)
{
    if(remain==0)return 1;
    if(dp[remain][pos])return dp[remain][pos];

    long long ret=1;//alone
    for(auto nxt:adj[pos])
        if((remain&(1<<colour[nxt])))ret=ret+rec(remain-(1<<colour[nxt]),nxt);

    dp[remain][pos]=ret;
    return ret;
}
int main()
{
    scanf("%i%i%i",&n,&m,&k);
    for(int i=1;i<=n;i++)
    {
        scanf("%i",&colour[i]);
        colour[i]--;
    }

    int u,v;
    for(int i=1;i<=m;i++)
    {
        scanf("%i%i",&u,&v);
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    long long ret=0;
    for(int i=1;i<=n;i++)
        ret=ret+rec((1<<k)-1-(1<<colour[i]),i)-1;

    printf("%lld\n",ret);
    return 0;
}

Compilation message (stderr)

paths.cpp: In function 'int main()':
paths.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i%i",&n,&m,&k);
     ~~~~~^~~~~~~~~~~~~~~~~~~
paths.cpp:28:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%i",&colour[i]);
         ~~~~~^~~~~~~~~~~~~~~~~
paths.cpp:35:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%i%i",&u,&v);
         ~~~~~^~~~~~~~~~~~~~

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