add new solutions

solutions/11/q1117/solution.go

@@ -0,0 +1,38 @@
+package q1117
+
+type void struct{}
+
+type H2O struct {
+	h, o, hRel chan void
+}
+
+func NewH2O() *H2O {
+	h := &H2O{
+		h:    make(chan void, 2),
+		o:    make(chan void, 2),
+		hRel: make(chan void, 2),
+	}
+	h.o <- void{}
+	return h
+}
+
+func (h *H2O) Hydrogen(releaseHydrogen func()) {
+	<-h.h
+	// releaseHydrogen() outputs "H". Do not change or remove this line.
+	releaseHydrogen()
+
+	h.hRel <- void{} // confirmation
+}
+
+func (h *H2O) Oxygen(releaseOxygen func()) {
+	<-h.o
+
+	// releaseOxygen() outputs "H". Do not change or remove this line.
+	releaseOxygen()
+
+	h.h <- void{}
+	h.h <- void{}
+	<-h.hRel
+	<-h.hRel
+	h.o <- void{}
+}