将C ++转换为Java-在无向图中打印所有循环

Question

我正在将C ++代码翻译成Java。

控制台中什么也不显示，它很快终止了。我的代码有什么问题？

结果应该是：

周期数1：3 4 5 6

周期2：11 12 13

我不确定该怎么写：cycles [mark [i]]。push_back（i）;

我编写的Java代码：

import java.util.ArrayList;

public class Graf { 
    static ArrayList <Integer> graph = new java.util.ArrayList<Integer>();
    static ArrayList <Integer> cycles = new java.util.ArrayList<Integer>();
    public static void dfs_cycle(int u, int p, int color[], int mark[], int par[], int cyclenumber) { 
        // already (completely) visited vertex. 
        if (color[u] == 2) {
            return; 
        } 

        // seen vertex, but was not completely visited -> cycle detected. 
        // backtrack based on parents to find the complete cycle. 
        if (color[u] == 1) { 
            cyclenumber++; 
            int cur = p; 
            mark[cur] = cyclenumber; 

            // backtrack the vertex which are 
            // in the current cycle thats found 
            while (cur != u) { 
                cur = par[cur]; 
                mark[cur] = cyclenumber; 
            } 
            return; 
        } 
        par[u] = p; 

        // partially visited. 
        color[u] = 1; 

        // simple dfs on graph 
        for (int v=0; v < graph.size(); v++) { 
            // if it has not been visited previously 
            if (v == par[u]) { 
                continue; 
            } 
            dfs_cycle(v, u, color, mark, par, cyclenumber); 
        } 

        // completely visited. 
        color[u] = 2; 
    } 

    // add the edges to the graph 
    static void addEdge(int u, int v) 
    { 
        graph.add(v);
        graph.add(u);
    } 

    // Function to print the cycles 
    static void printCycles(int edges, int mark[], int cyclenumber) { 

        // push the edges that into the cycle adjacency list 
        for (int i = 1; i <= edges; i++) { 
            if (mark[i] != 0) 
                cycles.add(i);
        } 

        // print all the vertex with same cycle 
        for (int i = 1; i <= cyclenumber; i++) { 
            // Print the i-th cycle 
            System.out.println("Cycle Number" + i + ": ");
            for (int x = 0; x < cycles.size(); x++) { 
                System.out.println(cycles.get(x) + " ");
            }
            System.out.println();
        } 
    } 

    public static void main(String [] args) { 
        addEdge(1, 2); 
        //and so on...

        // arrays required to color the graph, store the parent of node 
        int color[] = new int [100000];
        int par[] = new int [100000]; 

        // mark with unique numbers 
        int mark[] = new int [100000]; 

        // store the numbers of cycle 
        int cyclenumber = 0; 
        int edges = 13; 

        // call DFS to mark the cycles 
        dfs_cycle(1, 0, color, mark, par, cyclenumber); 

        // function to print the cycles 
        printCycles(edges, mark, cyclenumber); 
    } 
    }

这是C ++中的原始代码：

#include <bits/stdc++.h> 
using namespace std; 
const int N = 100000; 

vector<int> graph[N]; 
vector<int> cycles[N]; 

void dfs_cycle(int u, int p, int color[], 
            int mark[], int par[], int& cyclenumber) { 
    if (color[u] == 2) { 
        return; 
    }

    if (color[u] == 1) {
        cyclenumber++; 
        int cur = p; 
        mark[cur] = cyclenumber; 

        while (cur != u) {
            cur = par[cur];
            mark[cur] = cyclenumber; 
        } 
        return; 
    } 
    par[u] = p;
    color[u] = 1;
    for (int v : graph[u]) {
        if (v == par[u]) {
            continue;
        }
        dfs_cycle(v, u, color, mark, par, cyclenumber); 
    }
    color[u] = 2;
}

void addEdge(int u, int v) {
    graph[u].push_back(v); 
    graph[v].push_back(u); 
}    
void printCycles(int edges, int mark[], int& cyclenumber) {
    for (int i = 1; i <= edges; i++) { 
        if (mark[i] != 0) 
            cycles[mark[i]].push_back(i); 
    } 

    for (int i = 1; i <= cyclenumber; i++) { 
        cout << "Cycle Number " << i << ": "; 
        for (int x : cycles[i]) 
            cout << x << " "; 
        cout << endl; 
    }
}
int main() 
{ 
    addEdge(1, 2); 
    //and so on...

    int color[N]; 
    int par[N]; 

    int mark[N]; 

    int cyclenumber = 0; 
    int edges = 13; 

    dfs_cycle(1, 0, color, mark, par, cyclenumber); 

    printCycles(edges, mark, cyclenumber); 
}