查找每条边的间接节点(在R中)

library(igraph)

# 创建有向图
g <- graph_from_literal(A-B, B-C, C-D, D-A)

# 获取图的邻接列表
adj_list <- get.adjlist(g)

# 查找每条边的间接节点
indirect_nodes <- list()

for (i in 1:length(adj_list)) {
  node <- adj_list[[i]][[1]]
  indirect_nodes[[i]] <- list()
  
  for (j in 1:length(adj_list[[i]])) {
    neighbor <- adj_list[[i]][[j]]
    
    for (k in 1:length(adj_list[[neighbor]])) {
      indirect_node <- adj_list[[neighbor]][[k]]
      
      if (indirect_node != node && !indirect_node %in% adj_list[[i]]) {
        indirect_nodes[[i]][[length(indirect_nodes[[i]]) + 1]] <- indirect_node
      }
    }
  }
}

# 打印每条边的间接节点
for (i in 1:length(indirect_nodes)) {
  node <- names(adj_list)[i]
  neighbors <- adj_list[[i]]
  indirect <- indirect_nodes[[i]]
  
  for (j in 1:length(neighbors)) {
    neighbor <- neighbors[[j]]
    indirect_neighbor <- indirect[[j]]
    
    cat("边", node, "-", neighbor, "的间接节点为:", indirect_neighbor, "\n")
  }
}