#include <cstdio>
#include <set>
#include <cstring>
#include <cctype>
#include <vector>
#include <algorithm>
using namespace std;
const int MaxN = 500010,
MaxM = 2*500010;
typedef pair<int,int> pii;
struct node {
int next, edge;
};
pii mpair (int a, int b) {
return pair<int, int> (min(a,b), max(a,b));
}
set<pii> SS;
int LN = 1;
node L[MaxM];
int E[MaxM][3];
int pr[MaxN] = {0}, C[MaxN];
int N, M, a, b;
bool visited[MaxN] = {0};
vector<int> path;
int newv = -1, u;
int getU (int i, int v) {
return (v == E[i][0]) ? E[i][1] : E[i][0];
}
const int Maxl = 7000005;
char S[Maxl];
void printInt (int t) {
int pnt = 0;
int d = 100000;
while (d > 1 && t / d == 0) d /= 10;
for ( ; d > 0; d /= 10)
S[pnt++] = '0' + t / d % 10;
S[pnt++] = ' ';
S[pnt] = '\0';
printf("%s", S);
}
void dfs(int v) {
path.clear();
path.push_back(v);
while (v != -1) {
visited[v] = true;
newv = -1;
while (pr[v] != -1) {
int i = L[pr[v]].edge;
pr[v] = L[pr[v]].next;
u = getU(i, v);
if (SS.find(mpair(u, v)) == SS.end()) {
SS.insert(mpair(u, v));
if (visited[u]) {
bool ar = false;
newv = u;
int pnt = 0;
while (!ar) {
//printf("%d ", path.back());
if (path.back() == u) ar = true;
int d = 100000, t = path.back();
while (d > 1 && t / d == 0) d /= 10;
for ( ; d > 0; d /= 10) S[pnt++] = '0' + t / d % 10;
S[pnt++] = ' ';
visited[path.back()] = false;
path.pop_back();
}
S[pnt] = '\0';
printf("%s\n", S);
path.push_back(u);
//printf("%d\n", path.back());
}else {
newv = u;
path.push_back(u);
}
break;
}
}
if (newv == -1 and path.size() > 1) {
newv = path.back();
path.pop_back();
}
v =newv;
}
//visited[path[0]] = false;
}
void Parse(char lin[], int &a, int &b)
{
int slen = strlen(lin);
int pnt = 0;
a = 0; b = 0;
while (isdigit(lin[pnt])) {
a = 10 * a + lin[pnt] - '0';
pnt++;
}
while (!isdigit(lin[pnt])) pnt++;
while (pnt < slen && isdigit(lin[pnt])) {
b = 10 * b + lin[pnt] - '0';
pnt++;
}
}
int main() {
path.reserve(MaxN);
scanf("%d%d\n", &N, &M);
for (int i = 0; i < M; i++) {
int a, b;
gets(S);
Parse (S, a, b);
E[i][0] = a;
E[i][1] = b;
if (pr[a] == 0)
pr[a] = LN;
else
L[C[a]].next = LN;
if (pr[b] == 0)
pr[b] = LN+1;
else
L[C[b]].next = LN+1;
C[a] = LN;
C[b] = LN+1;
L[LN].next = -1;
L[LN].edge = i;
L[LN+1].next = -1;
L[LN+1].edge = i;
LN += 2;
}
for (int i = 1; i <= N; i++)
dfs(i);
return 0;
}
Compilation message
postmen.cpp: In function 'int main()':
postmen.cpp:120:3: error: 'gets' was not declared in this scope; did you mean 'getU'?
120 | gets(S);
| ^~~~
| getU
postmen.cpp:116:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
116 | scanf("%d%d\n", &N, &M);
| ~~~~~^~~~~~~~~~~~~~~~~~
