Feedback on ex0.* and ex1.*
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6 changed files with 47 additions and 21 deletions
12
ex0.2/gen_rand_explicit.py
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12
ex0.2/gen_rand_explicit.py
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@ -0,0 +1,12 @@
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#!/usr/bin/env python3
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import numpy as np
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import sys
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N = 1e6
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if len(sys.argv) > 1:
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N = float(sys.argv[1])
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for _ in range(int(N)):
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print( np.random.rand(1) )
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@ -1,4 +1,10 @@
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Running `time ./gen_rand.py "1e9"` gives
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Running `time ./gen_rand.py "1e6"` gives
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real 0m13.803s
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user 0m8.874s
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real 0m0.237s
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user 0m0.160s
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Contrast this to the following:
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Running `time ./gen_rand_explicit.py "1e6"` gives
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real 2m11.564s
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user 2m1.950s
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@ -19,15 +19,15 @@ int main() {
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unsigned int chars_capital = 0, chars_lower = 0, chars_digits = 0, chars_other = 0;
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while ( *ptr != 0 )
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{
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if ( *ptr >= int('A') && *ptr <= int('Z') )
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if ( *ptr >= 'A' && *ptr <= 'Z' )
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{
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++chars_capital;
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}
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else if ( *ptr >= int('a') && *ptr <= int('z') )
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else if ( *ptr >= 'a' && *ptr <= 'z' )
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{
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++chars_lower;
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}
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else if ( *ptr >= int('0') && *ptr <= int('9') )
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else if ( *ptr >= '0' && *ptr <= '9' )
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{
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++chars_digits;
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}
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@ -39,7 +39,9 @@ char* join(const char* str1 , const char* str2)
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char* joinb(const char* str1 , const char* str2)
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{
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int size = strlen(str1) + strlen(str2) + 1;
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// size should be 2 more than required for the strlens to
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// incorporate the space and the null byte
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int size = strlen(str1) + strlen(str2) + 2;
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char* new_str = new char[size];
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*new_str = 0;
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@ -15,12 +15,25 @@
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#define MEMORY_SIZE_IN_CHARS G
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void make_throwaway_ptrs(int leak_size ) {
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for ( int i = 0; i < leak_size ; i++)
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{
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char* throwaway_ptr = new char;
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}
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// oops, we are not returning the pointers
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// this means it goes out of scope when the function ends
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}
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int main() {
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char* throwaway_ptr = new char[MEMORY_SIZE_IN_CHARS];
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make_throwaway_ptrs(MEMORY_SIZE_IN_CHARS);
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std::cout << "We leaked " << MEMORY_SIZE_IN_CHARS * sizeof " " << " bits" << std::endl;
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std::cout << "Ready to kill the process? (press Enter)" << std::endl;
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std::cin.ignore();
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return 0;
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}
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@ -23,10 +23,10 @@
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#include <iostream>
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#include <cmath>
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#define VERBOSE false
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#define VERBOSE true
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char b32_lookup_table[] = "ABCDEFGHIJKLMNOPQRSTUV";
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int base = 8;
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char b32_lookup_table[] = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
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int base = 32;
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int main() {
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//a
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@ -75,7 +75,7 @@ int main() {
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digits[digit_num] = number & lsb_bitmask;
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// Shift off the bits we have put in to the array
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number = ( number >> bits_in_char );
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number >>= bits_in_char;
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++digit_num;
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}
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@ -91,14 +91,7 @@ int main() {
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// Loop the other way so the first digit we get out is MSB
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while ( digit_num >= 0 )
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{
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if ( digits[digit_num] < 10 )
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{
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std::cout << digits[digit_num];
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}
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else
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{
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std::cout << b32_lookup_table[digits[digit_num] - 10];
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}
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std::cout << b32_lookup_table[digits[digit_num]];
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digit_num--;
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}
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