Add subs and grph

07_subs/sample.txt

@@ -0,0 +1,2 @@
+GATATATGCATATACTT
+ATAT

07_subs/subs.nim

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+import os
+import std/streams
+import std/sequtils
+from std/strutils import join
+
+proc findNeedleInHaystack(s, t: string): seq[int] =
+    var occurrences = newSeq[int]()
+
+    for i in 0 ..< s.len:
+        var j = 0
+        while j < t.len and (i+j) < s.len and s[i+j] == t[j]:
+            inc j
+        if j == t.len:
+            occurrences.add(i+1)
+
+    return occurrences
+
+proc parseStream(stream: Stream): (string, string) =
+    let s = readLine(stream)
+    let t = readLine(stream)
+    return (s, t)
+
+let fileName = paramStr(1)
+let fileStream = newFileStream(fileName)
+if not isNil(fileStream):
+    let (s, t) = parseStream(fileStream)
+    let occurrences = findNeedleInHaystack(s, t)
+    echo occurrences.mapIt($it).join(" ")
+    fileStream.close()