Crazy Circuits HDU - 3157（有源汇有上下界最小流）

给出每条边的下界 求最小流

板题

提供两个板子代码 虽然这个题 第一个比较快

但在loj上https://loj.ac/problem/117

的板题  第一个1700+ms

第二个才600+ms  用输入挂后400+ms

#include <iostream>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <map>
#include <cctype>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#include <bitset>
#define rap(i, a, n) for(int i=a; i<=n; i++)
#define rep(i, a, n) for(int i=a; i<n; i++)
#define lap(i, a, n) for(int i=n; i>=a; i--)
#define lep(i, a, n) for(int i=n; i>a; i--)
#define rd(a) scanf("%d", &a)
#define rlld(a) scanf("%lld", &a)
#define rc(a) scanf("%c", &a)
#define rs(a) scanf("%s", a)
#define rb(a) scanf("%lf", &a)
#define rf(a) scanf("%f", &a)
#define pd(a) printf("%d\n", a)
#define plld(a) printf("%lld\n", a)
#define pc(a) printf("%c\n", a)
#define ps(a) printf("%s\n", a)
#define MOD 2018
#define LL long long
#define ULL unsigned long long
#define Pair pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define _  ios_base::sync_with_stdio(0),cin.tie(0)
//freopen("1.txt", "r", stdin);
using namespace std;
const int maxn = 1e5 + , INF = 0x7fffffff;
int n, m, s, t;
int head[maxn], cur[maxn], vis[maxn], nex[maxn << ], in[maxn];
int d[maxn];
int cnt;
struct node
{
    int u, v;
    int c;
}Node[maxn << ];

void add_(int u, int v, int c)
{
    Node[cnt].u = u;
    Node[cnt].v = v;
    Node[cnt].c = c;
    nex[cnt] = head[u];
    head[u] = cnt++;
}

void add(int u, int v, int c)
{
    add_(u, v, c);
    add_(v, u, );
}

bool bfs()
{
    queue<int> Q;
    mem(d, );
    Q.push(s);
    d[s] = ;
    while(!Q.empty())
    {
        int u = Q.front(); Q.pop();
        for(int i = head[u]; i != -; i = nex[i])
        {
            int v = Node[i].v;
            if(!d[v] && Node[i].c > )
            {
                d[v] = d[u] + ;
                Q.push(v);
                if(v == t) return ;
            }
        }
    }
    return d[t] != ;
}

int dfs(int u, int cap)
{
    int ret = ;
    if(u == t || cap == )
        return cap;
    for(int &i = cur[u]; i != -; i = nex[i])
    {
        int v = Node[i].v;
        if(d[v] == d[u] +  && Node[i].c > )
        {
            int V = dfs(v, min(cap, Node[i].c));
            Node[i].c -= V;
            Node[i ^ ].c += V;
            ret += V;
            cap -= V;
            if(cap == ) break;
        }
    }
    if(cap > ) d[u] = -;
    return ret;
}

int Dinic()
{
    int ans = ;
    while(bfs())
    {
        memcpy(cur, head, sizeof head);
        ans += dfs(s, INF);
    }
    return ans;
}

int tranf(string x)
{
    if(x == "+") return ;
    if(x == "-") return n + ;
    int ans = , len = x.size();
    for(int i = ; i < len; i++)
    {
        ans += (x[i] - '') * pow(, len - i - );
    }
    return ans + ;
}

int main()
{
    int w;
    string u, v;
    int u_, v_;
    while(~scanf("%d%d", &n, &m))
    {
        if(n ==  && m == ) break;
        mem(head, -);
        cnt = ;
        mem(in, );
        int sum = ;
        s = , t = n + ;
        rap(i, , m)
        {
            // scanf(" %c %c %d", &u, &v, &w);
            cin >> u >> v >> w;
            u_ = tranf(u);
            v_ = tranf(v);
            add(u_, v_, INF - w);
            in[v_] += w;
            in[u_] -= w;
        }
        for(int i = ; i <= n + ; i++)
        {
            if(in[i] > )
            {
                sum += in[i];
                add(s, i, in[i]);
            }
            else
                add(i, t, -in[i]);
        }
        int ans = Dinic();
        add(n + , , INF);
        ans += Dinic();
        if(sum == ans)
            cout << Node[head[(n + )] ^ ].c << endl;
        else
            cout << "impossible" << endl;

    }
    return ;
}

#include <iostream>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <map>
#include <cctype>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#include <bitset>
#define rap(i, a, n) for(int i=a; i<=n; i++)
#define rep(i, a, n) for(int i=a; i<n; i++)
#define lap(i, a, n) for(int i=n; i>=a; i--)
#define lep(i, a, n) for(int i=n; i>a; i--)
#define rd(a) scanf("%d", &a)
#define rlld(a) scanf("%lld", &a)
#define rc(a) scanf("%c", &a)
#define rs(a) scanf("%s", a)
#define rb(a) scanf("%lf", &a)
#define rf(a) scanf("%f", &a)
#define pd(a) printf("%d\n", a)
#define plld(a) printf("%lld\n", a)
#define pc(a) printf("%c\n", a)
#define ps(a) printf("%s\n", a)
#define MOD 2018
#define LL long long
#define ULL unsigned long long
#define Pair pair<int, int>
#define mem(a, b) memset(a, b, sizeof(a))
#define _  ios_base::sync_with_stdio(0),cin.tie(0)
//freopen("1.txt", "r", stdin);
using namespace std;
const int maxn = 1e5 + , INF = 0x7fffffff;
int n, m, s, t;
int head[maxn], cur[maxn], vis[maxn], nex[maxn << ], in[maxn];
int d[maxn];
int cnt;
struct node
{
    int u, v, bz;
    int c;
}Node[maxn << ];

void add_(int u, int v, int c, int bz)
{
    Node[cnt].u = u;
    Node[cnt].v = v;
    Node[cnt].c = c;
    Node[cnt].bz = bz;
    nex[cnt] = head[u];
    head[u] = cnt++;
}

void add(int u, int v, int c, int bz)
{
    add_(u, v, c, bz);
    add_(v, u, , bz);
}

bool bfs()
{
    queue<int> Q;
    mem(d, );
    Q.push(s);
    d[s] = ;
    while(!Q.empty())
    {
        int u = Q.front(); Q.pop();
        for(int i = head[u]; i != -; i = nex[i])
        {
            int v = Node[i].v;
            if(!d[v] && Node[i].c > )
            {
                d[v] = d[u] + ;
                Q.push(v);
                if(v == t) return ;
            }
        }
    }
    return d[t] != ;
}

int dfs(int u, int cap)
{
    int ret = ;
    if(u == t || cap == )
        return cap;
    for(int &i = cur[u]; i != -; i = nex[i])
    {
        int v = Node[i].v;
        if(d[v] == d[u] +  && Node[i].c > )
        {
            int V = dfs(v, min(cap, Node[i].c));
            Node[i].c -= V;
            Node[i ^ ].c += V;
            ret += V;
            cap -= V;
            if(cap == ) break;
        }
    }
    if(cap > ) d[u] = -;
    return ret;
}

int Dinic()
{
    int ans = ;
    while(bfs())
    {
        memcpy(cur, head, sizeof head);
        ans += dfs(s, INF);
    }
    return ans;
}

int tranf(string x)
{
    if(x == "+") return ;
    if(x == "-") return n + ;
    int ans = , len = x.size();
    for(int i = ; i < len; i++)
    {
        ans += (x[i] - '') * pow(, len - i - );
    }
    return ans + ;
}

int main()
{
    int w;
    string u, v;
    int u_, v_;
    while(~scanf("%d%d", &n, &m))
    {
        if(n ==  && m == ) break;
        mem(head, -);
        cnt = ;
        mem(in, );
        int sum = ;
        s = , t = n + ;
        rap(i, , m)
        {
            // scanf(" %c %c %d", &u, &v, &w);
            cin >> u >> v >> w;
            u_ = tranf(u);
            v_ = tranf(v);
            add(u_, v_, INF - w, );
            in[v_] += w;
            in[u_] -= w;
        }
        for(int i = ; i <= n + ; i++)
        {
            if(in[i] > )
            {
                sum += in[i];
                add(s, i, in[i], );
            }
            else
                add(i, t, -in[i], );
        }
        add(n + , , INF, );
        if(sum != Dinic())
            ps("impossible");
        else
        {
            sum = Node[head[n + ] ^ ].c;
            for(int i = ; i < cnt; i++)
            {
                if(!Node[i].bz) Node[i].v = ;
            }
            head[s] = head[t] = -;
            s = n + ;
            t = ;
            cout << sum - Dinic() << endl;
        }

    }
    return ;
}