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法律研究执行图的边缘着色的 C++ 程序
在本程序中，我们将执行图的边缘着色，其中我们必须给图的边缘着色，使得没有两条相邻的边具有相同的颜色。示例中的步骤。
算法
Begin Take the input of the number of vertices, n, and then number of edges, e, in the graph. The graph is stored as adjacency list. BFS is implemented using queue and colors are assigned to each edge. End
示例
#include<bits/stdc++.h>
using namespace std;
int n, e, i, j;
vector<vector<pair<int, int> > > g;
vector<int> color;
bool v[111001];
void col(int n) {
queue<int> q;
int c = 0;
set<int> vertex_colored;
if(v[n])
return;
v[n] = 1;
for(i = 0;i<g[n].size();i++) {
if(color[g[n][i].second]!=-1) {
vertex_colored.insert(color[g[n][i].second]);
}
}
for(i = 0;i<g[n].size();i++) {
if(!v[g[n][i].first]) {
q.push(g[n][i].first);
}
if(color[g[n][i].second]==-1) {
while(vertex_colored.find(c)!=vertex_colored.end())
c++;
color[g[n][i].second] = c;
vertex_colored.insert(c);
c++;
}
}
while(!q.empty()) {
int temp = q.front();
q.pop();
col(temp);
}
return;
}
int main() {
int u,w;
set<int> empty;
cout<<"Enter number of vertices and edges respectively:";
cin>>n>>e;
cout<<"\n";
g.resize(n); //number of vertices
color.resize(e,-1); //number of edges
memset(v,0,sizeof(v));
for(i = 0;i<e;i++) {
cout<<"\nEnter edge vertices of edge "<<i+1<<" :"<<"\n";
cin>>u>>w;
u--; w--;
g[u].push_back(make_pair(w,i));
g[w].push_back(make_pair(u,i));
}
col(0);
for(i = 0;i<e;i++) {
cout<<"Edge "<<i+1<<" is coloured with colour "<<color[i]+1
<< "\n";
}
}输出
Enter number of vertices and edges respectively:4 5 Enter edge vertices of edge 1 :1 2 Enter edge vertices of edge 2 :2 3 Enter edge vertices of edge 3 :1 1 Enter edge vertices of edge 4 :3 4 Enter edge vertices of edge 5 :1 4 Edge 1 is coloured with colour 1 Edge 2 is coloured with colour 2 Edge 3 is coloured with colour 2 Edge 4 is coloured with colour 1 Edge 5 is coloured with colour 3
更新于：2019 年 7 月 30 日
541 次浏览
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