go: add «1208. Get Equal Substrings Within Budget»

Signed-off-by: Matej Focko <me@mfocko.xyz>

go/get-equal-substrings-within-budget.go

@@ -0,0 +1,29 @@
+package get_equal_substrings_within_budget
+
+func equalSubstring(s string, t string, maxCost int) int {
+	abs := func(x int) int {
+		return max(x, -x)
+	}
+
+	getCost := func(i int) int {
+		return abs(int(s[i]) - int(t[i]))
+	}
+
+	mostOptimal := 0
+
+	begin := 0
+
+	cost := 0
+	for i, _ := range t {
+		cost += getCost(i)
+
+		for cost > maxCost {
+			cost -= getCost(begin)
+			begin++
+		}
+
+		mostOptimal = max(mostOptimal, i-begin+1)
+	}
+
+	return mostOptimal
+}