ACM/ICPC DFS Solution Euler pathway Path (POJ2337)

After judging the Oraton road, the DFS simple pruning solves the Euler path with the smallest dictionary order.

Time:16ms memory:228k#include<iostream> #include <cstring> #include <cstdio> #include <    algorithm>using namespace std; #define MAX 1005#define maxs 24//Name # define MAXN 26//Letter struct edge{char name[maxs];    int A, B; friend bool operator < (Edge &e1, Edge &e2) {return strcmp (E1.name, E2.name) < 0;}}    E[max];int N;int IN[MAXN], OUT[MAXN];     In degrees and out of int order[max];    Sequential path bool V[max];bool dfs (int x, int rk) {if (RK = = N) return true;            for (int i = 0; i < n; i++) {if (!v[i] && x = = e[i].a) {V[i] = true;            ORDER[RK] = i;            if (Dfs (e[i].b, rk+1)) return true;        V[i] = false; }} return false;}    int main () {//freopen ("In.txt", "R", stdin);    int T;    scanf ("%d", &t);        while (t--) {memset (e,0,sizeof (e));        memset (In,0,sizeof (in));        Memset (out,0,sizeof (out));        memset (order,-1,sizeof (order));        memset (v,false,sizeof (v)); scanf ("%d", &AMP;N);    composition int st = 26;            ST: Start for (int i = 0; i < n; i++) {scanf ("%s", e[i].name);            E[I].A = e[i].name[0]-' a ';            e[i].b = E[i].name[strlen (e[i].name)-1]-' a ';            out[e[i].a]++;            in[e[i].b]++;        if (E[i].a < st) St = E[I].A;        } sort (e,e+n);    Euler road judgment int odd = 0;        Number of singularity nodes bool flag = TRUE;                for (int i = 0; i < MAXN; i++) {if (In[i]! = Out[i]) {odd++;                if (Out[i]-in[i] = = 1) st = i;                    else if (Out[i]-in[i]! =-1) {flag = false;                Break         }}} if (flag && odd ==2 | | odd = 0) && dfs (st,0))//Meet Oraton Road (exclude non-connected) + Full path (non-connected)            {for (int i = 0; i < n-1; i++) printf ("%s.", E[order[i]].name); printf ("%s\n", E[ordeR[n-1]].name);    } else printf ("***\n"); } return 0;}

ACM/ICPC DFS Solution Euler pathway Path (POJ2337)