add new solutions

solutions/7/q739/solution.go

@@ -0,0 +1,19 @@
+package q739
+
+func dailyTemperatures(temperatures []int) []int {
+	waitDays := make([]int, len(temperatures))
+
+	idxStack := make([]int, 0, len(temperatures))
+	for i, temp := range temperatures {
+		for len(idxStack) > 0 && temperatures[idxStack[len(idxStack)-1]] < temp {
+			popped := idxStack[len(idxStack)-1]
+			idxStack = idxStack[:len(idxStack)-1] // pop
+
+			waitDays[popped] = i - popped
+		}
+		idxStack = append(idxStack, i)
+	}
+	return waitDays
+}
+
+var _ = dailyTemperatures