add new solutions

solutions/6/q693/solution.go

@@ -0,0 +1,15 @@
+package q693
+
+func hasAlternatingBits(n int) bool {
+	last := -1
+	for n > 0 {
+		if last == n%2 {
+			return false
+		}
+		last = n % 2
+		n >>= 1
+	}
+	return true
+}
+
+var _ = hasAlternatingBits

solutions/6/q696/solution.go

@@ -0,0 +1,20 @@
+package q696
+
+func countBinarySubstrings(s string) int {
+	cnt := 0
+	last := byte('0')
+	lastLen, curLen := 0, 0
+	for i := range len(s) {
+		if s[i] != last {
+			last, lastLen = s[i], curLen
+			curLen = 0
+		}
+		curLen++
+		if curLen <= lastLen {
+			cnt++
+		}
+	}
+	return cnt
+}
+
+var _ = countBinarySubstrings