POJ 刷题系列：3436. ACM Computer Factory
题意：
一个工厂，有n台机器，每台机器均有输入条件和输出结果，比如3个零件，机器1，输入0 0 1，表示输入机器1之前必须拥有零件3，输出 1 1 1，则表示通过该机器，能够制造出零件2。每台机器每小时也有它的最大产量w，问n台机器最多能制造多少台。
思路： 最大流，不要把机器当结点了，而是机器的每个输入和输出当结点，因为输出的结点可以进一步当作另外一台机器的输入。所以每台机器拆分成两个结点，i 和 i n，并且建立边容量为w[i]， 其次只有输入的零件均为0的结点才能与源点相连，只有输出零件全为1的结点连接汇点。其余关系边，只要一台机器的输入和前一台机器的输出不矛盾，就可以构造边。
代码如下：
代码语言：javascript复制package com.daimens.algorithm.january;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Map;
import java.util.Queue;
import java.util.StringTokenizer;
public class SolutionDay09_P3436 {
String INPUT = "./data/judge/201801/P3436.txt";
public static void main(String[] args) throws IOException {
new SolutionDay09_P3436().run();
}
static final int INF = 0x3f3f3f3f;
int[][] G;
int[] level;
int V;
void bfs(int s, int t) {
level = new int[V];
Arrays.fill(level, -1);
Queue<Integer> q = new ArrayDeque<Integer>();
q.offer(s);
level[s] = 0;
while (!q.isEmpty()) {
int now = q.poll();
for (int i = 0; i < V; i) {
if (G[now][i] > 0 && level[i] < 0) {
level[i] = level[now] 1;
q.offer(i);
}
}
}
}
int dfs(int s, int t, int f, boolean vis[]) {
if (s == t) return f;
vis[s] = true;
for (int i = 0; i < V; i) {
if (!vis[i] && G[s][i] > 0 && level[s] 1 == level[i]) {
int d = dfs(i, t, Math.min(G[s][i], f), vis);
if (d > 0) {
G[s][i] -= d;
G[i][s] = d;
return d;
}
}
}
return 0;
}
int dinic(int s, int t) {
int flow = 0;
for(;;) {
bfs(s, t);
if (level[t] < 0) break;
int f = 0;
while ((f = dfs(s, t, INF, new boolean[V])) > 0) flow = f;
}
return flow;
}
void read() {
while(more()) {
int p = ni();
int n = ni();
int[] w = new int[n];
int[][] input = new int[n][p];
int[][] output = new int[n][p];
for (int i = 0; i < n; i) {
w[i] = ni();
for (int j = 0; j < p; j) {
input[i][j] = ni();
}
for (int j = 0; j < p; j) {
output[i][j] = ni();
}
}
// build G
V = 2 * n 2;
G = new int[2 * n 2][2 * n 2];
for (int i = 1; i <= n; i) {
G[i][i n] = w[i - 1];
}
for (int i = 1; i <= n; i) {
for (int j = 1; j <= n; j) {
boolean ok = true;
for (int k = 0; k < p; k) {
if (input[j - 1][k] == 0 && output[i - 1][k] == 1 || input[j - 1][k] == 1 && output[i - 1][k] == 0) {
ok = false;
}
}
if (ok) {
G[i n][j] = Math.min(w[i - 1], w[j - 1]);
}
}
}
for (int i = 1; i <= n; i) {
boolean ok = true;
for (int k = 0; k < p; k) {
if (input[i - 1][k] == 1) ok = false;
}
if (ok) G[0][i] = INF;
ok = true;
for (int k = 0; k < p; k) {
if (output[i - 1][k] == 0) ok = false;
}
if (ok) G[i n][2 * n 1] = INF;
}
int[][] G2 = arrayCopy(G);
int flow = dinic(0, 2 * n 1);
int tot = 0;
int[][] ans = new int[n * n][3];
for (int i = 0; i < n; i) {
for (int j = 0; j < n; j) {
if (G2[i 1 n][j 1] > G[i 1 n][j 1]) {
ans[tot][0] = i 1;
ans[tot][1] = j 1;
ans[tot][2] = G2[i 1 n][j 1] - G[i 1 n][j 1];
tot ;
}
}
}
out.println(flow " " tot);
for (int i = 0; i < tot; i) {
out.println(ans[i][0] " " ans[i][1] " " ans[i][2]);
}
}
}
int[][] arrayCopy(int[][] G){
int n = G.length;
int m = G[0].length;
int[][] aux = new int[n][m];
for (int i = 0; i < n; i)
for (int j = 0; j < m; j)
aux[i][j] = G[i][j];
return aux;
}
FastScanner in;
PrintWriter out;
void run() throws IOException {
boolean oj;
try {
oj = ! System.getProperty("user.dir").equals("F:\oxygen_workspace\Algorithm");
} catch (Exception e) {
oj = System.getProperty("ONLINE_JUDGE") != null;
}
InputStream is = oj ? System.in : new FileInputStream(new File(INPUT));
in = new FastScanner(is);
out = new PrintWriter(System.out);
long s = System.currentTimeMillis();
read();
out.flush();
if (!oj){
System.out.println("[" (System.currentTimeMillis() - s) "ms]");
}
}
public boolean more(){
return in.hasNext();
}
public int ni(){
return in.nextInt();
}
public long nl(){
return in.nextLong();
}
public double nd(){
return in.nextDouble();
}
public String ns(){
return in.nextString();
}
public char nc(){
return in.nextChar();
}
class FastScanner {
BufferedReader br;
StringTokenizer st;
boolean hasNext;
public FastScanner(InputStream is) throws IOException {
br = new BufferedReader(new InputStreamReader(is));
hasNext = true;
}
public String nextToken() {
while (st == null || !st.hasMoreTokens()) {
try {
st = new StringTokenizer(br.readLine());
} catch (Exception e) {
hasNext = false;
return "##";
}
}
return st.nextToken();
}
String next = null;
public boolean hasNext(){
next = nextToken();
return hasNext;
}
public int nextInt() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Integer.parseInt(more);
}
public long nextLong() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Long.parseLong(more);
}
public double nextDouble() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Double.parseDouble(more);
}
public String nextString(){
if (next == null){
hasNext();
}
String more = next;
next = null;
return more;
}
public char nextChar(){
if (next == null){
hasNext();
}
String more = next;
next = null;
return more.charAt(0);
}
}
static class D{
public static void pp(int[][] board, int row, int col) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < row; i) {
for (int j = 0; j < col; j) {
sb.append(board[i][j] (j 1 == col ? "n" : " "));
}
}
System.out.println(sb.toString());
}
public static void pp(char[][] board, int row, int col) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < row; i) {
for (int j = 0; j < col; j) {
sb.append(board[i][j] (j 1 == col ? "n" : " "));
}
}
System.out.println(sb.toString());
}
}
static class ArrayUtils {
public static void fill(int[][] f, int value) {
for (int i = 0; i < f.length; i) {
Arrays.fill(f[i], value);
}
}
public static void fill(int[][][] f, int value) {
for (int i = 0; i < f.length; i) {
fill(f[i], value);
}
}
public static void fill(int[][][][] f, int value) {
for (int i = 0; i < f.length; i) {
fill(f[i], value);
}
}
}
static class Num{
public static <K> void inc(Map<K, Integer> mem, K k) {
if (!mem.containsKey(k)) mem.put(k, 0);
mem.put(k, mem.get(k) 1);
}
}
}
