feat: add solutions to lc problem: No.2171 (doocs#2238)

Author: Nothing-avil

solution/3000-3099/3008.Find Beautiful Indices in the Given Array II/Solution.go

@@ -0,0 +1,84 @@
+func beautifulIndices(s string, a string, b string, k int) []int {
+    
+    
+    s_len := len(s)
+    a_len := len(a)
+    b_len := len(b)
+    
+    final := make([]int, 0)
+    lps_a := make([]int, a_len)
+    lps_b := make([]int, b_len)
+    a_index := make([]int, 0)
+    b_index := make([]int, 0)
+    
+    var pat func(lps []int, s_l int, pattern string)
+
+    pat = func(lps []int, s_l int, pattern string){
+        
+        l := 0
+        lps[0] = 0
+        i := 1
+        
+        for i < s_l {
+            if pattern[i] == pattern[l] {
+                l++
+                lps[i] = l
+                i++
+            } else {
+                if l != 0 {
+                    l = lps[l-1]
+                } else {
+                    lps[i] = l
+                    i++
+                }
+            }   
+        }
+    }
+
+    pat(lps_a, a_len, a)
+    pat(lps_b, b_len, b)
+
+    var kmp func(pat string, pat_l int, lps []int, index *[]int)
+
+    kmp = func(pat string, pat_l int, lps []int, index *[]int){
+        i := 0
+        j := 0
+        for s_len - i >= pat_l - j {
+            if s[i] == pat[j]{
+                i++
+                j++
+            }
+            if j == pat_l{
+                *index = append(*index, i-pat_l)
+                j = lps[j-1]
+            } else if s[i] != pat[j] {
+                if j!=0 {
+                    j = lps[j-1]
+                } else {
+                    i++
+                }
+            }
+        }
+    }
+
+    kmp(a, a_len, lps_a, &a_index)
+    kmp(b, b_len, lps_b, &b_index)
+    
+    // fmt.Println(a_index, b_index)
+
+    i := 0
+    j := 0
+
+    for i < len(a_index) && j < len(b_index) {
+        if a_index[i]+k >= b_index[j] && a_index[i]-k <= b_index[j]{
+            final = append(final, a_index[i])
+            i++
+        } else if a_index[i] - k > b_index[j]{
+            j++
+        } else {
+            i++
+        }
+    }
+    
+    return final
+}