#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 ----------
int parent1[100000],parent2[100000];
int find(int n,int *parent) {
if (parent[n] != n) parent[n] = find(parent[n],parent);
return parent[n];
}
vpii adjList[100000];
int disc[100000],low[100000],num = 0;
int doDFS(int u,int p) {
int i;
disc[u] = low[u] = num++;
for (i = 0; i < adjList[u].size(); i++) {
int v = adjList[u][i].first;
if (disc[v] == -1) {
doDFS(v,adjList[u][i].second);
low[u] = min(low[u],low[v]);
if (low[v] > disc[u]) cout << u+1 << " " << v+1 << endl;
}
else if (adjList[u][i].second != p) low[u] = min(low[u],disc[v]);
}
return 0;
}
int main() {
int i;
int N,M,u,v;
scanf("%d %d",&N,&M);
for (i = 0; i < N; i++) parent1[i] = parent2[i] = i;
for (i = 0; i < M; i++) {
scanf("%d %d",&u,&v);
u--,v--;
int pu = find(u,parent1),pv = find(v,parent1);
if (pu != pv) {
parent1[pu] = pv;
adjList[u].pb(mp(v,i));
adjList[v].pb(mp(u,i));
}
else {
pu = find(u,parent2),pv = find(v,parent2);
if (pu != pv) {
parent2[pu] = pv;
adjList[u].pb(mp(v,i));
adjList[v].pb(mp(u,i));
}
}
}
for (i = 0; i < N; i++) disc[i] = low[i] = -1;
for (i = 0; i < N; i++) {
if (disc[i] == -1) doDFS(i,-1);
}
return 0;
}
Compilation message
pipes.cpp: In function 'int doDFS(int, int)':
pipes.cpp:68:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (i = 0; i < adjList[u].size(); i++) {
~~^~~~~~~~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:82:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d",&N,&M);
~~~~~^~~~~~~~~~~~~~~
pipes.cpp:85:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d",&u,&v);
~~~~~^~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
2688 KB |
Output is correct |
2 |
Correct |
4 ms |
2688 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
3200 KB |
Output is correct |
2 |
Correct |
8 ms |
3072 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
119 ms |
3100 KB |
Output is correct |
2 |
Correct |
114 ms |
2944 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
208 ms |
3892 KB |
Output is correct |
2 |
Correct |
249 ms |
3496 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
360 ms |
5624 KB |
Output is correct |
2 |
Correct |
305 ms |
5132 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
550 ms |
11320 KB |
Output is correct |
2 |
Correct |
489 ms |
8504 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
760 ms |
12672 KB |
Output is correct |
2 |
Correct |
711 ms |
9264 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1002 ms |
15036 KB |
Output is correct |
2 |
Correct |
997 ms |
11004 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1316 ms |
14984 KB |
Output is correct |
2 |
Correct |
1271 ms |
10972 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1506 ms |
14372 KB |
Output is correct |
2 |
Correct |
1393 ms |
11056 KB |
Output is correct |