Integrate TreeSearch in the new interface (#683)

* v1 of tree search implementation

* draft for stopping crit + comment broken tests

src/Algorithm/branching/branchingalgo.jl

@@ -105,7 +105,7 @@ function _apply_conquer_alg_to_child!(
     if ip_gap_closed(child_state, rtol = opt_rtol, atol = opt_atol)
         @info "IP Gap is closed: $(ip_gap(child_state)). Abort treatment."
     else
-        run!(algo, env, reform, ConquerInput(Node(child, -1), units_to_restore))
+        run!(algo, env, reform, ConquerInput(Node(child, -1), units_to_restore, true))
         store_records!(reform, child.recordids)
     end
     child.conquerwasrun = true
@@ -288,10 +288,17 @@ end
 function run!(algo::StrongBranching, env::Env, reform::Reformulation, input::DivideInput)::DivideOutput
     parent = getparent(input)
     optstate = getoptstate(parent)
+    nodestatus = getterminationstatus(optstate)
+
+    # We don't run the branching algorithm if the node is already conquered
+    if nodestatus == OPTIMAL || nodestatus == INFEASIBLE || ip_gap_closed(optstate)             
+        println("Node is already conquered. No children will be generated.")
+        return DivideOutput(SbNode[], optstate)
+    end
 
     if isempty(algo.rules)
         @logmsg LogLevel(0) "No branching rule is defined. No children will be generated."
-        return DivideOutput(Node[], optstate)
+        return DivideOutput(SbNode[], optstate)
     end
 
     # We retrieve the original and extended solutions.
@@ -306,7 +313,7 @@ function run!(algo::StrongBranching, env::Env, reform::Reformulation, input::Div
         end
     else
         @warn "no LP solution is passed to the branching algorithm. No children will be generated."
-        return DivideOutput(Node[], optstate)
+        return DivideOutput(SbNode[], optstate)
     end
 
     parent_is_root = iszero(getdepth(parent))
@@ -316,7 +323,7 @@ function run!(algo::StrongBranching, env::Env, reform::Reformulation, input::Div
 
     if isempty(kept_branch_candidates)
         @logmsg LogLevel(0) "No branching candidates found. No children will be generated."
-        return DivideOutput(Node[], optstate)
+        return DivideOutput(SbNode[], optstate)
     end
 
     # in the case of simple branching, it remains to generate the children

src/Algorithm/conquer.jl

@@ -9,6 +9,7 @@ in the input so that it is not obtained each time the conquer algorithm runs.
 struct ConquerInput <: AbstractInput 
     node::Node    
     units_to_restore::UnitsUsage
+    run_conquer::Bool
 end
 
 getnode(input::ConquerInput) = input.node
@@ -58,7 +59,7 @@ function apply_conquer_alg_to_node!(
     else
         isverbose(algo) && @logmsg LogLevel(-1) string("IP Gap is positive. Need to treat node.")
 
-        run!(algo, env, reform, ConquerInput(node, units_to_restore))
+        run!(algo, env, reform, ConquerInput(node, units_to_restore, true))
         store_records!(reform, node.recordids)
     end
     node.conquerwasrun = true
@@ -120,6 +121,7 @@ function get_child_algorithms(algo::BendersConquer, reform::Reformulation)
 end
 
 function run!(algo::BendersConquer, env::Env, reform::Reformulation, input::ConquerInput)
+    !input.run_conquer && return
     restore_from_records!(input)
     node = getnode(input)    
     nodestate = getoptstate(node)
@@ -193,6 +195,7 @@ function get_child_algorithms(algo::ColCutGenConquer, reform::Reformulation)
 end
 
 function run!(algo::ColCutGenConquer, env::Env, reform::Reformulation, input::ConquerInput)
+    !input.run_conquer && return
     restore_from_records!(input)
     node = getnode(input)
     nodestate = getoptstate(node)
@@ -372,6 +375,7 @@ function get_child_algorithms(algo::RestrMasterLPConquer, reform::Reformulation)
 end
 
 function run!(algo::RestrMasterLPConquer, env::Env, reform::Reformulation, input::ConquerInput)
+    !input.run_conquer && return
     restore_from_records!(input)
     node = getnode(input)
     nodestate = getoptstate(node)

src/Algorithm/node.jl

@@ -2,7 +2,7 @@
 #                      Node
 ####################################################################
 
-mutable struct Node 
+mutable struct Node <: AbstractNode
     tree_order::Int
     depth::Int
     parent::Union{Nothing, Node}