The Necklace UVA10054

#include <iostream>#include <cstdio>#include <cstdlib>#include <cmath>#include <queue>#include <algorithm>#include <vector>#include <cstring>#include <stack>#include <cctype>#include <utility>   #include <map>#include <string>  #include <climits> #include <set>#include <string>    #include <sstream>#include <utility>   #include <ctime>using std::priority_queue;using std::vector;using std::swap;using std::stack;using std::sort;using std::max;using std::min;using std::pair;using std::map;using std::string;using std::cin;using std::cout;using std::set;using std::queue;using std::string;using std::istringstream;using std::make_pair;using std::greater;using std::endl;const int MAXN(60);int degree[MAXN];int is_euler(int mn){int s = -1;for(int i = 1; i <= mn; ++i)if(degree[i]){if(s == -1)s = i;if(degree[i]%2)return -1;}return s;}stack<pair<int, int> > st;int mp[MAXN][MAXN];void dfs(int cur, int mn){for(int i = 1; i <= mn; ++i)if(mp[cur][i]){--mp[cur][i];--mp[i][cur];dfs(i, mn);st.push(make_pair(cur, i));}}int main(){int T, n_case(0);bool println(false);scanf("%d", &T);while(T--){int N;scanf("%d", &N);int u, v, mn = 1;memset(degree, 0, sizeof(degree));memset(mp, 0, sizeof(mp));for(int i = 0; i < N; ++i){scanf("%d%d", &u, &v);++degree[u];++degree[v];++mp[u][v];++mp[v][u];mn = max(mn, max(u, v));}int flag = is_euler(mn);if(println)printf("\n");println = true;printf("Case #%d\n", ++n_case);if(flag == -1)printf("some beads may be lost\n");else{dfs(flag, mn);while(!st.empty()){printf("%d %d\n", st.top().first, st.top().second);st.pop();}}}return 0;}