Submission #1518976


Source Code Expand

#define TEST_MODE true

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include "bits/stdc++.h"
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep2(i, a, b) for (int i = (a); i < (int)(b); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, a, b) for (int i = (a)-1; i >= (int)b; --i)
#define range(i, a, b, c) for (int i = a;             \
                               c > 0 ? i < b : i > b; \
                               i += c)
#define chmax(a, b) (a = (a) < (b) ? (b) : (a))
#define chmin(a, b) (a = (a) > (b) ? (b) : (a))
using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define all(a) begin(a), end(a)
#define ifnot(a) if (not(a))
#define int long long

#ifdef LOCAL_ENV

#if TEST_MODE == true
const bool test = true;
#define dump(x) cerr << #x << " = " << (x) << endl
#else
const bool test = false;
#define dump(x) 
#endif

#else
const bool test = false;
#define dump(x) 
#endif

int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
const int INF = (int)1 << 60;
const ll INFL = (ll)1 << 60;
ll mod_n = (int)1e9 + 7;
const double eps = 1e-10;
typedef long double Real;
// return -1, 0, 1
int sgn(const Real &r) { return (r > eps) - (r < -eps); }
int sgn(const Real &a, const Real &b) { return sgn(a - b); }

//.....................
const int MAX = (int)2e5 + 5;

vector<string> split(const string &str, char sep)
{
    vector<string> v;
    stringstream ss(str);
    string buffer;
    while (getline(ss, buffer, sep))
    {
        v.push_back(buffer);
    }
    return v;
}

template <class InputIterator>
int sum(InputIterator begin, InputIterator end)
{
    return accumulate(begin, end, 0ll);
}

void solve();

class Solver {
public:
    int N, M;
    vector<int> graph[MAX];

    bool ok() {
        rep(i, graph[1].size()) {
            int cur = graph[1][i];
            rep(j, graph[cur].size()) {
                if (graph[cur][j] == N) return true;
            }
        }
        return false;
    }

    void solve() {
        cin >> N >> M;
        rep(i, M) {
            int a, b;
            cin >> a >> b;
            graph[a].push_back(b);
            graph[b].push_back(a);
        }
        cout << (ok() ? "POSSIBLE": "IMPOSSIBLE") << endl;
    }
};

signed main()
{
    cout << fixed << setprecision(20);
    auto ptr = new Solver();
    ptr->solve();
    delete ptr;
    // while (true) {    
    //     auto ptr = new Solver();
    //     ptr->solve();
    //     delete ptr;
    // }
    return 0;
}

// class Mycin {
// 	bool flag = true;
// public:
// 	Mycin& operator >> (int& a) {flag = scanf("%lld", &a) != EOF; return *this;}
// 	Mycin& operator >> (char& a) {flag = scanf("%c", &a) != EOF; return *this;}
// 	Mycin& operator >> (string& s) {flag = (bool)(cin >> s); return *this;}
// 	operator bool() {return flag;}
// } mycin;
 
// class Mycout {
// public:
// 	Mycout& operator << (const int& a) {printf("%lld", a); return *this;}
// 	Mycout& operator << (const char c) {printf("%c", c); return *this;}
// 	Mycout& operator << (const string& s) {printf("%s", s.c_str()); return *this;}
// } mycout;
 
// #define cin mycin
// #define cout mycout
// #define endl '\n'


Submission Info

Submission Time
Task C - Cat Snuke and a Voyage
User naimonon77
Language C++14 (GCC 5.4.1)
Score 300
Code Size 3346 Byte
Status AC
Exec Time 159 ms
Memory 12776 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 300 / 300
Status
AC × 4
AC × 11
Set Name Test Cases
Sample example0, example1, example2, example3
All example0, example1, example2, example3, last0, last1, many0, many1, rand0, rand1, rand2
Case Name Status Exec Time Memory
example0 AC 3 ms 4992 KB
example1 AC 3 ms 4992 KB
example2 AC 3 ms 4992 KB
example3 AC 3 ms 4992 KB
last0 AC 159 ms 11904 KB
last1 AC 154 ms 11904 KB
many0 AC 128 ms 12776 KB
many1 AC 127 ms 12776 KB
rand0 AC 99 ms 9856 KB
rand1 AC 156 ms 11776 KB
rand2 AC 87 ms 9472 KB