Submission #136657

#	Time	Username	Problem	Language	Result	Execution time	Memory
136657		Alliance	Port Facility (JOI17_port_facility)	C++14	22 / 100	107 ms	16444 KiB

port_facility

// In the Name of Allah
#include<bits/stdc++.h>
#define double long double
typedef long long ll;
const ll MAX_N = 2000+100;
const ll MOD = 1e9+7;
using namespace std;

vector<int> g[MAX_N];
bool mark[MAX_N];
int cl[MAX_N];
pair<int,int> lr[MAX_N];
int n,cnt;

bool intersect(int i,int j){
    if (lr[i].first>lr[j].second or lr[j].first>lr[i].second)
        return false;
    if (lr[i].first<=lr[j].first and lr[j].second<=lr[i].second)
        return false;
    swap(i,j);
    if (lr[i].first<=lr[j].first and lr[j].second<=lr[i].second)
        return false;
    return true;
}

void no(){
    cout << 0;
    exit(0);
}

void dfs(int v)
{
    mark[v]++;
    for(auto x:g[v]){
        if (mark[x]){
            if (cl[x]==cl[v])
                no();
        }
        else{
            cl[x] = 3-cl[v];
            dfs(x);
        }
    }
}

int main()
{
    cin >> n;
    for(int i = 1;i<=n;++i)
        scanf("%d%d",&lr[i].first,&lr[i].second);
    if (n>2000)
        exit(1);
    for(int i = 1;i<=n;++i){
        for(int j = 1;j<=n;++j){
            if (intersect(i,j))
                g[i].push_back(j);
        }
    }
    for(int i = 1;i<=n;++i){
        if (mark[i])
            continue;
        cnt++;
        cl[i] = 1;
        dfs(i);
    }
    ll ans = 1;
    for(int i = 1;i<=cnt;++i)
        ans *= 2,ans %= MOD;
    cout << ans;
    return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'void dfs(int)':
port_facility.cpp:33:12: warning: use of an operand of type 'bool' in 'operator++' is deprecated [-Wdeprecated]
     mark[v]++;
            ^~
port_facility.cpp: In function 'int main()':
port_facility.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&lr[i].first,&lr[i].second);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22