HDU 3338 Kakuro Extension

网络最大流

TLE了两天的题目。80次Submit才AC，发现是刘汝佳白书的Dinic代码还可以优化。。。。。瞬间无语。。。。。

 

#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;

const int maxn = 30000 + 10;
const int INF = 0x7FFFFFFF;
struct Edge
{
    int from, to, cap, flow;
    Edge(int u, int v, int c, int f) :from(u), to(v), cap(c), flow(f) {}
};
vector<Edge>edges;
vector<int>G[maxn];
bool vis[maxn];
int d[maxn];
int cur[maxn];
int n, m, s, t;

void init()
{
    for (int i = 0; i < maxn; i++)
        G[i].clear();
    edges.clear();
}
void AddEdge(int from, int to, int cap)
{
    edges.push_back(Edge(from, to, cap, 0));
    edges.push_back(Edge(to, from, 0, 0));
    int w = edges.size();
    G[from].push_back(w - 2);
    G[to].push_back(w - 1);
}
bool BFS()
{
    memset(vis, 0, sizeof(vis));
    queue<int>Q;
    Q.push(s);
    d[s] = 0;
    vis[s] = 1;
    while (!Q.empty())
    {
        int x = Q.front();
        Q.pop();
        for (int i = 0; i<G[x].size(); i++)
        {
            Edge e = edges[G[x][i]];
            if (!vis[e.to] && e.cap>e.flow)
            {
                vis[e.to] = 1;
                d[e.to] = d[x] + 1;
                Q.push(e.to);
            }
        }
    }
    return vis[t];
}
int DFS(int x, int a)
{
    if (x == t || a == 0)
        return a;
    int flow = 0, f;
    for (int &i = cur[x]; i<G[x].size(); i++)
    {
        Edge e = edges[G[x][i]];
        if (d[x]+1 == d[e.to]&&(f=DFS(e.to,min(a,e.cap-e.flow)))>0)
        {
            edges[G[x][i]].flow+=f;
            edges[G[x][i] ^ 1].flow-=f;
            flow+=f;
            a-=f;
            if(a==0) break;
        }
    }
    if(!flow) d[x] = -1;
    return flow;
}
int dinic(int s, int t)
{
    int flow = 0;
    while (BFS())
    {
        memset(cur, 0, sizeof(cur));
        flow += DFS(s, INF);
    }
    return flow;
}

//输入输出
int N, M;
char S[1000];
int Map1[105][105];//横向
int Map2[105][105];//纵向
int BH[105][105];
int FLAG[maxn];

int main()
{
    while (~scanf("%d%d", &N, &M))
    {

        edges.clear();
        for (int i = 0; i<maxn; i++) G[i].clear();
        memset(Map1, 0, sizeof(Map1));
        memset(Map2, 0, sizeof(Map2));
        memset(BH, 0, sizeof(BH));
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= M; j++)
            {
                scanf("%s", S);
                if (S[3] == '.') continue;
                if (S[3] == 'X') Map1[i][j] = -1, Map2[i][j] = -1;
                else
                {
                    if (S[2] == 'X')
                    {
                        Map2[i][j] = -1;
                        Map1[i][j] = (S[4] - '0') * 100 + (S[5] - '0') * 10 + (S[6] - '0') * 1;
                    }
                    else if (S[4] == 'X')
                    {
                        Map1[i][j] = -1;
                        Map2[i][j] = (S[0] - '0') * 100 + (S[1] - '0') * 10 + (S[2] - '0') * 1;
                    }
                    else
                    {
                        Map1[i][j] = (S[4] - '0') * 100 + (S[5] - '0') * 10 + (S[6] - '0') * 1;
                        Map2[i][j] = (S[0] - '0') * 100 + (S[1] - '0') * 10 + (S[2] - '0') * 1;
                    }
                }
            }
        int Tot = 1;
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= M; j++)
                if (Map1[i][j] == 0)
                    BH[i][j] = Tot, Tot++;
        int Duan = Tot - 1;//方格编号1--Duan
        s = 0;
        t = 30000;
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= M; j++)
            {
                if (Map1[i][j] != -1 && Map1[i][j] != 0)
                {
                    int Zong = 0;
                    for (int k = j + 1;; k++)
                    {
                        if (k>M || Map1[i][k] != 0) break;
                        AddEdge(Tot, BH[i][k], 8);
                        Zong++;
                    }
                    AddEdge(s, Tot, Map1[i][j] - Zong);
                    Tot++;
                }
            }
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= M; j++)
            {
                if (Map2[i][j] != -1 && Map2[i][j] != 0)
                {
                    int Zong = 0;
                    for (int k = i + 1;; k++)
                    {
                        if (Map2[k][j] != 0 || k>N) break;
                        AddEdge(BH[k][j], Tot, 8);
                        Zong++;
                    }
                    AddEdge(Tot, t, Map2[i][j] - Zong);
                    Tot++;
                }
            }
        dinic(s, t);
        memset(FLAG, 0, sizeof FLAG);
        for (int i = 0; i<edges.size(); i = i + 2)
            if (edges[i].from >= 1 && edges[i].from <= Duan)
                FLAG[edges[i].from] = edges[i].flow;
        for (int i = 1; i <= N; i++)
        {
            for (int j = 1; j <= M; j++)
            {
                if (BH[i][j] == 0) printf("_");
                else printf("%d", FLAG[BH[i][j]] + 1);
                if (j<M) printf(" ");
            }
            printf("\n");
        }
    }
    return 0;
}