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Merged
suisen-cp merged 10 commits into from
Sep 12, 2020
Merged

MaxFlow #4

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b567072
Merge pull request #20 from suisen-cp/master
NASU41 Sep 9, 2020
16c5456
format
falrnd Sep 9, 2020
7b35ac2
exception
falrnd Sep 9, 2020
a95a345
groups
falrnd Sep 9, 2020
98ad085
Merge pull request #22 from falrnd/master
NASU41 Sep 9, 2020
b7efd40
Merge pull request #21 from suisen-cp/master
suisen-cp Sep 9, 2020
7b8fca7
Merge pull request #23 from suisen-cp/SegTree
NASU41 Sep 9, 2020
e76f682
Merge remote-tracking branch 'upstream/master' into two-sat
suisen-cp Sep 9, 2020
29b4928
Merge branch 'master' of https://github.com/suisen-cp/AtCoderLibraryF…
suisen-cp Sep 10, 2020
0245629
MaxFlow
suisen-cp Sep 12, 2020
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141 changes: 72 additions & 69 deletions DSU/DSU.java
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Original file line number Diff line number Diff line change
@@ -1,70 +1,73 @@
class DSU{
private int n;
private int[] parentOrSize;

public DSU(int n){
this.n = n;
this.parentOrSize = new int[n];
Arrays.fill(parentOrSize,-1);
}

int merge(int a, int b){
if(!(0 <= a && a < n) || !(0 <= b && b < n)){
// この式が成立しない物は動作しません。
return -1;
}
int x = leader(a);
int y = leader(b);
if(x == y) return x;
if(-parentOrSize[x] < -parentOrSize[y]){
int tmp = x;
x = y;
y = tmp;
}
parentOrSize[x] += parentOrSize[y];
parentOrSize[y] = x;
return x;
}

boolean same(int a, int b){
if(!(0 <= a && a < n) || !(0 <= b && b < n)){
// この式が成立しない物は動作しません。
return false;
}
return leader(a) == leader(b);
}

int leader(int a){
if (parentOrSize[a] < 0){
return a;
}else{
parentOrSize[a] = leader(parentOrSize[a]);
return parentOrSize[a];
}
}
import java.util.ArrayList;
import java.util.Arrays;

int size(int a) {
if(!(0 <= a && a < n)){
// この式が成立しない物は動作しません。
return -1;
}
return -parentOrSize[leader(a)];
}

ArrayList<ArrayList<Integer>> groups(){
int[] leaderBuf = new int[n];
int[] groupSize = new int[n];
for(int i = 0; i < n; i++){
leaderBuf[i] = leader(i);
groupSize[leaderBuf[i]]++;
}
ArrayList<ArrayList<Integer>> result = new ArrayList<ArrayList<Integer>>();
for(int i = 0; i < n; i++){
result.add(new ArrayList<>());
}
for(int i = 0; i < n; i++){
result.get(leaderBuf[i]).add(i);
}
return result;
}
}
class DSU {
private int n;
private int[] parentOrSize;

public DSU(int n) {
this.n = n;
this.parentOrSize = new int[n];
Arrays.fill(parentOrSize, -1);
}

int merge(int a, int b) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("a=" + a);
if (!(0 <= b && b < n))
throw new IndexOutOfBoundsException("b=" + b);

int x = leader(a);
int y = leader(b);
if (x == y) return x;
if (-parentOrSize[x] < -parentOrSize[y]) {
int tmp = x;
x = y;
y = tmp;
}
parentOrSize[x] += parentOrSize[y];
parentOrSize[y] = x;
return x;
}

boolean same(int a, int b) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("a=" + a);
if (!(0 <= b && b < n))
throw new IndexOutOfBoundsException("b=" + b);
return leader(a) == leader(b);
}

int leader(int a) {
if (parentOrSize[a] < 0) {
return a;
} else {
parentOrSize[a] = leader(parentOrSize[a]);
return parentOrSize[a];
}
}

int size(int a) {
if (!(0 <= a && a < n))
throw new IndexOutOfBoundsException("" + a);
return -parentOrSize[leader(a)];
}

ArrayList<ArrayList<Integer>> groups() {
int[] leaderBuf = new int[n];
int[] groupSize = new int[n];
for (int i = 0; i < n; i++) {
leaderBuf[i] = leader(i);
groupSize[leaderBuf[i]]++;
}
ArrayList<ArrayList<Integer>> result = new ArrayList<>(n);
for (int i = 0; i < n; i++) {
result.add(new ArrayList<>(groupSize[i]));
}
for (int i = 0; i < n; i++) {
result.get(leaderBuf[i]).add(i);
}
result.removeIf(ArrayList::isEmpty);
return result;
}
}
210 changes: 210 additions & 0 deletions MaxFlow/MaxFlow.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,210 @@
class MaxFlow {
public class CapEdge {
private final int from, to;
private long cap;
private final int rev;
CapEdge(int from, int to, long cap, int rev) {
this.from = from;
this.to = to;
this.cap = cap;
this.rev = rev;
}
public int getFrom() {return from;}
public int getTo() {return to;}
public long getCap() {return cap;}
public long getFlow() {return g[to][rev].cap;}
}

private static final long INF = Long.MAX_VALUE;

private final int n;
private int m;
private final java.util.ArrayList<CapEdge> edges;
private final int[] count;
private final CapEdge[][] g;

public MaxFlow(int n) {
this.n = n;
this.edges = new java.util.ArrayList<>();
this.count = new int[n];
this.g = new CapEdge[n][];
}

public int addEdge(int from, int to, long cap) {
vertexRangeCheck(from);
vertexRangeCheck(to);
capNonNegativeCheck(cap);
CapEdge e = new CapEdge(from, to, cap, count[to]);
count[from]++; count[to]++;
edges.add(e);
return m++;
}

public CapEdge getEdge(int i) {
edgeRangeCheck(i);
return edges.get(i);
}

public java.util.ArrayList<CapEdge> getEdges() {
return edges;
}

public void changeEdge(int i, long newCap, long newFlow) {
edgeRangeCheck(i);
capNonNegativeCheck(newCap);
if (newFlow > newCap) {
throw new IllegalArgumentException(
String.format("Flow %d is greater than capacity %d.", newCap, newFlow)
);
}
CapEdge e = edges.get(i);
CapEdge er = g[e.to][e.rev];
e.cap = newCap - newFlow;
er.cap = newFlow;
}

private void buildGraph() {
for (int i = 0; i < n; i++) {
g[i] = new CapEdge[count[i]];
}
int[] idx = new int[n];
for (CapEdge e : edges) {
g[e.to][idx[e.to]++] = new CapEdge(e.to, e.from, 0, idx[e.from]);
g[e.from][idx[e.from]++] = e;
}
}

public long maxFlow(int s, int t) {
return flow(s, t, INF);
}

public long flow(int s, int t, long flowLimit) {
vertexRangeCheck(s);
vertexRangeCheck(t);
buildGraph();
long flow = 0;
int[] level = new int[n];
int[] que = new int[n];
int[] iter = new int[n];
while (true) {
java.util.Arrays.fill(level, -1);
dinicBFS(s, t, level, que);
if (level[t] < 0) return flow;
java.util.Arrays.fill(iter, 0);
while (true) {
long d = dinicDFS(t, s, flowLimit - flow, iter, level);
if (d <= 0) break;
flow += d;
}
}
}

private void dinicBFS(int s, int t, int[] level, int[] que) {
int hd = 0, tl = 0;
que[tl++] = s;
level[s] = 0;
while (tl > hd) {
int u = que[hd++];
for (CapEdge e : g[u]) {
int v = e.to;
if (e.cap <= 0 || level[v] >= 0) continue;
level[v] = level[u] + 1;
if (v == t) return;
que[tl++] = v;
}
}
}

private long dinicDFS(int cur, int s, long f, int[] iter, int[] level) {
if (cur == s) return f;
long res = 0;
while (iter[cur] < count[cur]) {
CapEdge er = g[cur][iter[cur]++];
int u = er.to;
CapEdge e = g[u][er.rev];
if (level[u] >= level[cur] || e.cap <= 0) continue;
long d = dinicDFS(u, s, Math.min(f - res, e.cap), iter, level);
if (d <= 0) continue;
e.cap -= d;
er.cap += d;
res += d;
if (res == f) break;
}
return res;
}

public long fordFulkersonMaxFlow(int s, int t) {
return fordFulkersonFlow(s, t, INF);
}

public long fordFulkersonFlow(int s, int t, long flowLimit) {
vertexRangeCheck(s);
vertexRangeCheck(t);
buildGraph();
boolean[] used = new boolean[n];
long flow = 0;
while (true) {
java.util.Arrays.fill(used, false);
long f = fordFulkersonDFS(s, t, flowLimit - flow, used);
if (f <= 0) return flow;
flow += f;
}
}

private long fordFulkersonDFS(int cur, int t, long f, boolean[] used) {
if (cur == t) return f;
used[cur] = true;
for (CapEdge e : g[cur]) {
if (used[e.to] || e.cap <= 0) continue;
long d = fordFulkersonDFS(e.to, t, Math.min(f, e.cap), used);
if (d <= 0) continue;
e.cap -= d;
g[e.to][e.rev].cap += d;
return d;
}
return 0;
}

public boolean[] minCut(int s) {
vertexRangeCheck(s);
boolean[] reachable = new boolean[n];
int[] stack = new int[n];
int ptr = 0;
stack[ptr++] = s;
reachable[s] = true;
while (ptr > 0) {
int u = stack[--ptr];
for (CapEdge e : g[u]) {
int v = e.to;
if (reachable[v] || e.cap <= 0) continue;
reachable[v] = true;
stack[ptr++] = v;
}
}
return reachable;
}

private void vertexRangeCheck(int i) {
if (i < 0 || i >= n) {
throw new IndexOutOfBoundsException(
String.format("Index %d out of bounds for length %d", i, n)
);
}
}

private void edgeRangeCheck(int i) {
if (i < 0 || i >= m) {
throw new IndexOutOfBoundsException(
String.format("Index %d out of bounds for length %d", i, m)
);
}
}

private void capNonNegativeCheck(long cap) {
if (cap < 0) {
throw new IllegalArgumentException(
String.format("Capacity %d is negative.", cap)
);
}
}
}
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