图论 HDOJ 5348 MZL's endless loop

题目传送门

/*
    题意：给一个n个点,m条边的无向图,要求给m条边定方向,使得每个定点的出入度之差的绝对值小于等于1. 输出任意一种结果
    图论：一个图，必定存在偶数个奇度顶点。那么从一个奇度定点深搜，当碰到另外一个奇度顶点时结束，这样能保证度数差<=1
 3.5　 详细解释：http://blog.csdn.net/ZSGG_ACM/article/details/47287681　　
*/
/************************************************
 * Author        :Running_Time
 * Created Time  :2015-8-5 18:55:37
 * File Name     :F.cpp
 ************************************************/
#pragma comment (linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1
typedef long long ll;
const int MAXN = 1e5 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
struct Edge {
    int v, nex, dir;
}e[MAXN*6];
int head[MAXN];
int deg[MAXN];
int n, m, tot;

void init(void) {
    tot = 0;
    memset (head, -1, sizeof (head));
    memset (deg, 0, sizeof (deg));
}

void add_edge(int u, int v) {
    e[tot].v = v;
    e[tot].nex = head[u];
    e[tot].dir = 0;
    head[u] = tot++;
}

bool DFS(int u) {
    for (int &i=head[u]; ~i; i=e[i].nex)    {
        int v = e[i].v;
        int dir = e[i].dir ^ e[i^1].dir;
        if (dir)    continue;
        e[i].dir = 1;
        if (deg[v]) {
            deg[v] = 0; return true;
        }
        if (DFS (v))    return true;
    }
    return false;
}

void work(void) {
    for (int i=1; i<=n; ++i)    {
        if (deg[i]) {
            deg[i] = 0; DFS (i);
        }
    }
    for (int i=1; i<=n; ++i)    {
        while (~head[i])    DFS (i);
    }
    for (int i=0; i<tot; i+=2)  {
        if (e[i].dir)   puts ("1");
        else    puts ("0");
    }
}

int main(void)    {     //HDOJ 5348 MZL's endless loop
    int T;  scanf ("%d", &T);
    while (T--) {
        init ();
        scanf ("%d%d", &n, &m);
        for (int i=1; i<=m; ++i)    {
            int u, v;   scanf ("%d%d", &u, &v);
            deg[u] ^= 1;   deg[v] ^= 1;
            add_edge (u, v);    add_edge (v, u);
        }
        work ();
    }

    return 0;
}

/************************************************
 * Author        :Running_Time
 * Created Time  :2015-8-5 18:55:37
 * File Name     :F.cpp
 ************************************************/
#pragma comment (linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1
typedef long long ll;
const int MAXN = 1e5 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
struct Edge {
    int v, nex, vis;
}e[MAXN*6];
int head[MAXN];
int deg[MAXN];
int ans[MAXN*6];
int n, m, tot;

void init(void) {
    tot = 0;
    memset (head, -1, sizeof (head));
    memset (deg, 0, sizeof (deg));
}

void add_edge(int u, int v) {
    e[tot].v = v;
    e[tot].nex = head[u];
    e[tot].vis = 0;
    head[u] = tot++;
}

void DFS(int u) {
    for (int &i=head[u]; ~i; )    {
        int v = e[i].v;
        if (e[i].vis)   {
            i = e[i].nex;   continue;
        }
        e[i].vis = 1;   e[i^1].vis = 1;
        ans[i>>1] = i & 1;
        deg[u]--;   deg[v]--;
        i = e[i].nex;
        DFS (v);
    }
}

void patch(void) {
    int pre = -1;
    for (int i=1; i<=n; ++i)    {
        if (deg[i] & 1) {
            if (pre == -1)  {
                pre = i;
            }
            else    {
                add_edge (pre, i);  add_edge (i, pre);
                deg[pre]++; deg[i]++;
                pre = -1;
            }
        }
    }
}

void work(void) {
    patch ();
    for (int i=1; i<=n; ++i)    {
        if (deg[i]) DFS (i);
    }
    for (int i=0; i<m; ++i)    printf ("%d
", ans[i]);
}

int main(void)    {
    int T;  scanf ("%d", &T);
    while (T--) {
        init ();
        scanf ("%d%d", &n, &m);
        for (int i=1; i<=m; ++i)    {
            int u, v;   scanf ("%d%d", &u, &v);
            deg[u]++;   deg[v]++;
            add_edge (u, v);    add_edge (v, u);
        }
        work ();
    }

    return 0;
}