Merge pull request #140 from Ryoga-exe/refactor/FlowCalculator

refactor que.pop in FlowCalculator

Author: koba-e964

src/maxflow.rs

@@ -162,9 +162,7 @@ where
 self.level[self.s] = 0;
 self.que.clear();
 self.que.push(self.s);
-while !self.que.empty(){
-let v = *self.que.front().unwrap();
-self.que.pop();
+whileletSome(&v) = self.que.pop(){
 for e in&self.graph.g[v]{
 if e.cap == Cap::zero() || self.level[e.to] >= 0{
 continue;