GitHub/interactive-coding-challenges
1
0
Fork 0
mirror of https://github.com/donnemartin/interactive-coding-challenges synced 2026-01-07 18:08:01 +00:00
Code Issues Packages Projects Releases Wiki Activity

Restored original compression challenge

Browse Source
This commit is contained in:
Ashhar Hasan
2015-12-19 02:20:59 +05:30
parent 7d6b374380
commit bbb9b74f0f
3 changed files with 54 additions and 94 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
arrays_strings/compress/compress_challenge.ipynb
View File

@@ -18,7 +18,7 @@
"cell_type": "markdown", "cell_type": "markdown",
"metadata": {}, "metadata": {},
"source": [ "source": [
"## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3BCCD4'. Only compress the string if it saves space.\n", "## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3B1C2D4'. Only compress the string if it saves space.\n",
"\n", "\n",
"* [Constraints](#Constraints)\n", "* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n", "* [Test Cases](#Test-Cases)\n",
@@ -52,7 +52,7 @@
"* None -> None\n", "* None -> None\n",
"* '' -> ''\n", "* '' -> ''\n",
"* 'AABBCC' -> 'AABBCC'\n", "* 'AABBCC' -> 'AABBCC'\n",
"* 'AAABCCDDDD' -> 'A3BCCD4'" "* 'AAABCCDDDD' -> 'A3B1C2D4'"
] ]
}, },
{ {
@@ -118,7 +118,7 @@
" assert_equal(func(None), None)\n", " assert_equal(func(None), None)\n",
" assert_equal(func(''), '')\n", " assert_equal(func(''), '')\n",
" assert_equal(func('AABBCC'), 'AABBCC')\n", " assert_equal(func('AABBCC'), 'AABBCC')\n",
" assert_equal(func('AAABCCDDDD'), 'A3BCCD4')\n", " assert_equal(func('AAABCCDDDD'), 'A3B1C2D4')\n",
" print('Success: test_compress')\n", " print('Success: test_compress')\n",
"\n", "\n",
"\n", "\n",
@@ -143,21 +143,21 @@
], ],
"metadata": { "metadata": {
"kernelspec": { "kernelspec": {
"display_name": "Python 3", "display_name": "Python 2",
"language": "python", "language": "python",
"name": "python3" "name": "python2"
}, },
"language_info": { "language_info": {
"codemirror_mode": { "codemirror_mode": {
"name": "ipython", "name": "ipython",
"version": 3 "version": 2
}, },
"file_extension": ".py", "file_extension": ".py",
"mimetype": "text/x-python", "mimetype": "text/x-python",
"name": "python", "name": "python",
"nbconvert_exporter": "python", "nbconvert_exporter": "python",
"pygments_lexer": "ipython3", "pygments_lexer": "ipython2",
"version": "3.4.3" "version": "2.7.10"
} }
}, },
"nbformat": 4, "nbformat": 4,

129
arrays_strings/compress/compress_solution.ipynb
View File

@@ -18,7 +18,7 @@
"cell_type": "markdown", "cell_type": "markdown",
"metadata": {}, "metadata": {},
"source": [ "source": [
"## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3BCCD4'. Only compress the string if it saves space.\n", "## Problem: Compress a string such that 'AAABCCDDDD' becomes 'A3B1C2D4'. Only compress the string if it saves space.\n",
"\n", "\n",
"* [Constraints](#Constraints)\n", "* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n", "* [Test Cases](#Test-Cases)\n",
@@ -51,7 +51,7 @@
"* None -> None\n", "* None -> None\n",
"* '' -> ''\n", "* '' -> ''\n",
"* 'AABBCC' -> 'AABBCC'\n", "* 'AABBCC' -> 'AABBCC'\n",
"* 'AAABCCDDDD' -> 'A3BCCD4'" "* 'AAABCCDDDD' -> 'A3B1C2D4'"
] ]
}, },
{ {
@@ -69,20 +69,10 @@
" * For each char in string\n", " * For each char in string\n",
" * If char is the same as last_char, increment count\n", " * If char is the same as last_char, increment count\n",
" * Else\n", " * Else\n",
" * If the count is more than 2\n", " * Append last_char to compressed_string\n",
" * Append last_char to compressed_string\n", " * append count to compressed_string\n",
" * append count to compressed_string\n", " * count = 1\n",
" * count = 1\n", " * last_char = char\n",
" * last_char = char\n",
" * If count is 1\n",
" * Append last_char to compressed_string\n",
" * count = 1\n",
" * last_char = char\n",
" * If count is 2\n",
" * Append last_char to compressed_string\n",
" * Append last_char to compressed_string once more\n",
" * count = 1\n",
" * last_char = char\n",
" * Append last_char to compressed_string\n", " * Append last_char to compressed_string\n",
" * Append count to compressed_string\n", " * Append count to compressed_string\n",
" * Return compressed_string\n", " * Return compressed_string\n",
@@ -101,66 +91,47 @@
}, },
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": 4, "execution_count": 1,
"metadata": { "metadata": {
"collapsed": false "collapsed": false
}, },
"outputs": [], "outputs": [],
"source": [ "source": [
"def compress_string(string):\n", "def compress_string(string):\n",
"\tif string is None or len(string) == 0:\n", " if string is None or len(string) == 0:\n",
"\t\treturn string\n", " return string\n",
"\n", "\n",
"\t# Calculate the size of the compressed string\n", " # Calculate the size of the compressed string\n",
"\tsize = 0\n", " size = 0\n",
"\tlast_char = string[0]\n", " last_char = string[0]\n",
"\tfor char in string:\n", " for char in string:\n",
"\t\tif char != last_char:\n", " if char != last_char:\n",
"\t\t\tsize += 2\n", " size += 2\n",
"\t\t\tlast_char = char\n", " last_char = char\n",
"\tsize += 2\n", " size += 2\n",
"\n", "\n",
"\t# If the compressed string size is greater than\n", " # If the compressed string size is greater than\n",
"\t# or equal to string size, return original string\n", " # or equal to string size, return original string\n",
"\tif size >= len(string):\n", " if size >= len(string):\n",
"\t\treturn string\n", " return string\n",
"\n", "\n",
"\t# Create compressed_string\n", " # Create compressed_string\n",
"\t# New objective:\n", " compressed_string = list()\n",
"\t\t# Single characters are to be left as is\n", " count = 0\n",
"\t\t# Double characters are to be left as are\n", " last_char = string[0]\n",
"\tcompressed_string = list()\n", " for char in string:\n",
"\tcount = 0\n", " if char == last_char:\n",
"\tlast_char = string[0]\n", " count += 1\n",
"\tfor char in string:\n", " else:\n",
"\t\tif char == last_char:\n", " compressed_string.append(last_char)\n",
"\t\t\tcount += 1\n", " compressed_string.append(str(count))\n",
"\t\telse:\n", " count = 1\n",
"\t\t\t# Do the old compression tricks only if count exceeds two\n", " last_char = char\n",
"\t\t\tif count > 2:\n", " compressed_string.append(last_char)\n",
"\t\t\t\tcompressed_string.append(last_char)\n", " compressed_string.append(str(count))\n",
"\t\t\t\tcompressed_string.append(str(count))\n",
"\t\t\t\tcount = 1\n",
"\t\t\t\tlast_char = char\n",
"\t\t\t# If count is either 1 or 2 (or 0?)\n",
"\t\t\t# FIXME: CAN COUNT BE 0?\n",
"\t\t\telse:\n",
"\t\t\t\t# If count is 1, leave the char as is\n",
"\t\t\t\tif count == 1:\n",
"\t\t\t\t\tcompressed_string.append(last_char)\n",
"\t\t\t\t\tcount = 1\n",
"\t\t\t\t\tlast_char = char\n",
"\t\t\t\t# If count is 2, append the character twice\n",
"\t\t\t\telse:\n",
"\t\t\t\t\tcompressed_string.append(last_char)\n",
"\t\t\t\t\tcompressed_string.append(last_char)\n",
"\t\t\t\t\tcount = 1\n",
"\t\t\t\t\tlast_char = char\n",
"\tcompressed_string.append(last_char)\n",
"\tcompressed_string.append(str(count))\n",
"\n", "\n",
"\t# Convert the characters in the list to a string\n", " # Convert the characters in the list to a string\n",
"\treturn \"\".join(compressed_string)" " return \"\".join(compressed_string)"
] ]
}, },
{ {
@@ -172,7 +143,7 @@
}, },
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": 5, "execution_count": 2,
"metadata": { "metadata": {
"collapsed": false "collapsed": false
}, },
@@ -196,8 +167,7 @@
" assert_equal(func(None), None)\n", " assert_equal(func(None), None)\n",
" assert_equal(func(''), '')\n", " assert_equal(func(''), '')\n",
" assert_equal(func('AABBCC'), 'AABBCC')\n", " assert_equal(func('AABBCC'), 'AABBCC')\n",
" assert_equal(func('AAABCCDDDD'), 'A3BCCD4')\n", " assert_equal(func('AAABCCDDDD'), 'A3B1C2D4')\n",
" assert_equal(func('aaBCCEFFFFKKMMMMMMP taaammanlaarrrr seeeeeeeeek tooo'), 'aaBCCEF4KKM6P ta3mmanlaar4 se9k to3')\n",
" print('Success: test_compress')\n", " print('Success: test_compress')\n",
"\n", "\n",
"\n", "\n",
@@ -212,7 +182,7 @@
}, },
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": 7, "execution_count": 3,
"metadata": { "metadata": {
"collapsed": false "collapsed": false
}, },
@@ -228,34 +198,25 @@
"source": [ "source": [
"%run -i test_compress.py" "%run -i test_compress.py"
] ]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": []
} }
], ],
"metadata": { "metadata": {
"kernelspec": { "kernelspec": {
"display_name": "Python 3", "display_name": "Python 2",
"language": "python", "language": "python",
"name": "python3" "name": "python2"
}, },
"language_info": { "language_info": {
"codemirror_mode": { "codemirror_mode": {
"name": "ipython", "name": "ipython",
"version": 3 "version": 2
}, },
"file_extension": ".py", "file_extension": ".py",
"mimetype": "text/x-python", "mimetype": "text/x-python",
"name": "python", "name": "python",
"nbconvert_exporter": "python", "nbconvert_exporter": "python",
"pygments_lexer": "ipython3", "pygments_lexer": "ipython2",
"version": "3.4.3" "version": "2.7.10"
} }
}, },
"nbformat": 4, "nbformat": 4,

3
arrays_strings/compress/test_compress.py
View File

@@ -7,8 +7,7 @@ class TestCompress(object):
assert_equal(func(None), None) assert_equal(func(None), None)
assert_equal(func(''), '') assert_equal(func(''), '')
assert_equal(func('AABBCC'), 'AABBCC') assert_equal(func('AABBCC'), 'AABBCC')
assert_equal(func('AAABCCDDDD'), 'A3BCCD4') assert_equal(func('AAABCCDDDD'), 'A3B1C2D4')
assert_equal(func('aaBCCEFFFFKKMMMMMMP taaammanlaarrrr seeeeeeeeek tooo'), 'aaBCCEF4KKM6P ta3mmanlaar4 se9k to3')
print('Success: test_compress') print('Success: test_compress')