Submission #79052

#	Time	Username	Problem	Language	Result	Execution time	Memory
79052		duality	Potemkin cycle (CEOI15_indcyc)	C++11	100 / 100	67 ms	7196 KiB

indcyc

#define DEBUG 0

#include <bits/stdc++.h>
using namespace std;

#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}

// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
    public:
        template<typename T>
        _Debug& operator,(T val) {
            cout << val << endl;
            return *this;
        }
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif

// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back

// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;

// ---------- END OF TEMPLATE ----------

vi adjList[1000];
int order[1000],deg[1000];
priority_queue<pii> H;
set<int> S[1000];
int no[1000],parent[1000];
queue<int> Q;
int main() {
    int i;
    int N,R;
    int a,b;
    scanf("%d %d",&N,&R);
    for (i = 0; i < R; i++) {
        scanf("%d %d",&a,&b);
        a--,b--;
        adjList[a].pb(b);
        adjList[b].pb(a);
    }

    int j,c;
    a = -1;
    for (i = 0; i < N; i++) order[i] = -1,H.push(mp(0,i));
    for (i = 0; i < N; i++) {
        while (order[H.top().second] != -1) H.pop();
        int u = H.top().second,p = -1;
        H.pop();
        order[u] = i;
        for (j = 0; j < adjList[u].size(); j++) {
            int v = adjList[u][j];
            if (order[v] != -1) {
                S[u].insert(v);
                if ((p == -1) || (order[v] > order[p])) p = v;
            }
            else H.push(mp(++deg[v],v));
        }
        if (p != -1) {
            for (auto it = S[u].begin(); it != S[u].end(); it++) {
                if ((*it != p) && !S[p].count(*it)) {
                    a = u,b = p,c = *it;
                    break;
                }
            }
        }
        if (a != -1) break;
    }
    if (a == -1) printf("no\n");
    else {
        fill(parent,parent+N,-1);
        for (i = 0; i < adjList[a].size(); i++) {
            if (adjList[a][i] != c) no[adjList[a][i]] = 1;
        }
        no[a] = 1;
        Q.push(b);
        while (!Q.empty()) {
            int u = Q.front();
            Q.pop();

            if (u == c) break;
            for (i = 0; i < adjList[u].size(); i++) {
                int v = adjList[u][i];
                if ((parent[v] == -1) && !no[v]) {
                    parent[v] = u;
                    Q.push(v);
                }
            }
        }
        printf("%d",a+1);
        while (c != b) printf(" %d",c+1),c = parent[c];
        printf(" %d\n",b+1);
    }

    return 0;
}

Compilation message (stderr)

indcyc.cpp: In function 'int main()':
indcyc.cpp:84:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0; j < adjList[u].size(); j++) {
                     ~~^~~~~~~~~~~~~~~~~~~
indcyc.cpp:105:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i = 0; i < adjList[a].size(); i++) {
                     ~~^~~~~~~~~~~~~~~~~~~
indcyc.cpp:115:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (i = 0; i < adjList[u].size(); i++) {
                         ~~^~~~~~~~~~~~~~~~~~~
indcyc.cpp:68:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&N,&R);
     ~~~~~^~~~~~~~~~~~~~~
indcyc.cpp:70:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d",&a,&b);
         ~~~~~^~~~~~~~~~~~~~~
indcyc.cpp:114:13: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
             if (u == c) break;
             ^~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10