Merge remote-tracking branch 'upstream/master'

2 files changed, 120 insertions, 0 deletions

diff --git a/challenge-092/paulo-custodio/lua/ch-1.lua b/challenge-092/paulo-custodio/lua/ch-1.lua
new file mode 100644
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+++ b/challenge-092/paulo-custodio/lua/ch-1.lua
@@ -0,0 +1,57 @@
+#!/usr/bin/env lua
+
+--[[
+Challenge 092
+
+TASK #1 > Isomorphic Strings
+Submitted by: Mohammad S Anwar
+You are given two strings $A and $B.
+
+Write a script to check if the given strings are Isomorphic. Print 1 if they
+are otherwise 0.
+
+Example 1:
+Input: $A = "abc"; $B = "xyz"
+Output: 1
+Example 2:
+Input: $A = "abb"; $B = "xyy"
+Output: 1
+Example 3:
+Input: $A = "sum"; $B = "add"
+Output: 0
+--]]
+
+function split_string(str)
+    local t = {}
+    string.gsub(str, ".", function(c) table.insert(t,c) end)
+    return t
+end
+
+function isomorphic(a, b)
+    if #a ~= #b then
+        return 0
+    else
+        local a = split_string(a)
+        local b = split_string(b)
+        local mapping = {}
+        local mapped = {}
+
+        for i=1, #a do
+            if mapping[a[i]] == nil then        -- a is new
+                if mapped[b[i]] ~= nil then     -- b already mapped to some other a
+                    return 0
+                else                            -- store mapping
+                    mapping[a[i]] = b[i]
+                    mapped[b[i]] = 1
+                end
+            else                                -- a already occurred
+                if mapping[a[i]] ~= b[i] then   -- previous mapping is different
+                    return 0
+                end
+            end
+        end
+        return 1
+    end
+end
+
+io.write(isomorphic(arg[1], arg[2]))
diff --git a/challenge-092/paulo-custodio/lua/ch-2.lua b/challenge-092/paulo-custodio/lua/ch-2.lua
new file mode 100644
index 0000000000..5df3153e72
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+++ b/challenge-092/paulo-custodio/lua/ch-2.lua
@@ -0,0 +1,63 @@
+#!/usr/bin/env lua
+
+--[[
+Challenge 092
+
+TASK #2 > Insert Interval
+Submitted by: Mohammad S Anwar
+You are given a set of sorted non-overlapping intervals and a new interval.
+
+Write a script to merge the new interval to the given set of intervals.
+
+Example 1:
+Input $S = (1,4), (8,10); $N = (2,6)
+Output: (1,6), (8,10)
+Example 2:
+Input $S = (1,2), (3,7), (8,10); $N = (5,8)
+Output: (1,2), (3,10)
+Example 3:
+Input $S = (1,5), (7,9); $N = (10,11)
+Output: (1,5), (7,9), (10,11)
+--]]
+
+timeline = {}
+
+function fill_timeline()
+    for i=1,#arg do
+        -- parse begin,end
+        local bg, ed = string.match(arg[i], "(%d+),(%d+)")
+        bg = tonumber(bg)
+        ed = tonumber(ed)
+
+        -- resize timeline if needed
+        while 2*ed >= #timeline do
+            table.insert(timeline, false)
+        end
+
+        -- fill interval
+        for j=2*bg, 2*ed do
+            timeline[j] = true
+        end
+    end
+end
+
+function print_timeline()
+    -- collect intervals
+    local intervals = {}
+    for i=1, #timeline-1 do
+        if timeline[i] == false and timeline[i+1] == true then
+            table.insert(intervals, math.floor(i/2)+1)
+        elseif timeline[i] == true and timeline[i+1] == false then
+            table.insert(intervals, math.floor(i/2))
+        end
+    end
+
+    -- print intervals
+    for i=1, #intervals, 2 do
+        io.write("(",intervals[i],",",intervals[i+1],")")
+        if i+2 < #intervals then io.write(", ") end
+    end
+end
+
+fill_timeline()
+print_timeline()