CS103 Lecture 1 Slides Introduction Mark Redekopp 2 What is - - PowerPoint PPT Presentation
1 CS103 Lecture 1 Slides Introduction Mark Redekopp 2 What is Computer Science All science is computer science It is very interdisciplinary: Math, Engineering, Medicine, Natural sciences, Art, Linguistics, etc. Computer science is
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– Maria Klawe, et. al. - To the age-old question -- "What do you want to do when you grow up?" -- children today give many modern answers: "Help feed hungry families." "Prevent and cure diseases." "Find sources of renewable energy." "Understand the universe. One clear path leads to each of these aspirations: the study of computer science. http://www.huffingtonpost.com/maria-klawe/computing-our-childrens-f_b_388874.html
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extra time if you've never coded before
CSCI 101 or ITP 165, 109, or 115
solutions (not just any solution)
primary language (not Java)
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http://www.digibarn.com/collections/posters/tongues/ComputerLanguagesChart-med.png
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– Makes it fast & flexible (Near direct control of the HW) – Makes it dangerous (Near direct control of the HW) – Most common in embedded devices – C became popular because it was the language used to implement Unix & then Linux (all Unix/Linux distributions came with a C / C++ compiler)
– Used everywhere, even to implement other programming languages (i.e. Python, Matlab, etc.)
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– Overestimate the time you will need and your ability to get your work done – Limit extracurricular activities in the 1st semester – Don’t let shame or embarrassment keep you from the help you need
– It's like learning a musical instrument
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S F
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S F
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S F May just compute a straight line path from ‘S’ to ‘F’
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S F
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S F
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S
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S F 3 2 1 3 3 2 2 3 3 3 1 S 3 2 1 3 1 3 2 3 3 2 2 2 If you don’t know where F is and want to find the shortest path, you have to do it this way Uninformed search for shortest path: Breadth-first
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S F Select a square to explore with minimum distance to the finish 5 5 5 3
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4 S 2 4 F Select a square to explore with minimum distance to the finish 5 5 5 3
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– Now we would pick the best among the remainder.
4 S 2 4 F Select a square to explore with minimum distance to the finish 5 5 5 3
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– Now we would pick the best among the remainder.
S 2 Select a square to explore with minimum distance to the finish 5 5 5 3 F 4 4 4 4 3 5 4 1 2 F 5 5
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– Computer store information as numbers – These numbers are stored as units
processor is only capable to looking at 1 or 2 numbers simultaneously – Each pixel of the image is a separate piece of data
Processor RAM 32-64 bits
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11010010 01001011 10010000 11110100 01101000 11010001 … 00001011 1 2 3 4 5 1023 Address Data Memory Device
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– Read: retrieves data value in a particular location (specified using the address) – Write: changes data in a location to a new value
– Note: A group of wires/signals is referred to as a ‘bus’ – Thus, we say that memories have an address, data, and control bus.
11010010 01001011 10010000 11110100 01101000 11010001 … 00001011 1 2 3 4 5 1023 11010010 01001011 10010000 11110100 01101000 00000110 … 00001011 1 2 3 4 5 1023 2 10010000 Read Addr. Data Control Addr. Data Control 5 00000110 Write A Write Operation A Read Operation
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S 2 5 5 5 3 F 4 4 4 4 3 5 4 1 2 F 5 5
00000000 00000000 00000001 00000001 … 00001011 1 2 … 20 21 1023 Addr. Data Control
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Your Environment
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– A text editor to write the code – A ‘C/C++’ compiler, linker, etc. to convert the code to a program
– Mac XCode (Mac only) – MS Visual Studio (Windows only) – CodeBlocks (cross-platform)
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– Requires installation of Oracle VirtualBox and download of the Ubuntu Image – https://www.virtualbox.org/wiki/Downloads – Requires download of the VM Image http://bits.usc.edu/files/cs103/install/student-vm-2015.ova
– http://ee.usc.edu/~redekopp/Streaming/fa13_vm_walkthru/fa13_vm _walkthru.html
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– Anywhere in the code – C-Style => “/*” and “*/” – C++ Style => “//”
– #includes tell compiler what other library functions you plan on using – 'using namespace std;' -- Just do it for now!
– Starting point of execution for the program – Variable declarations often appear at the start
– All code/statements in C must be inside a function – Statements execute one after the next – Ends with a ‘return’ statement
/* Anything between slash-star and star-slash is ignored even across multiple lines of text or code */ /*----Section 1: Compiler Directives ----*/ #include <iostream> #include <cmath> using namespace std; /*------------ Section 2 ----------------*/ /*Global variables & Function Prototypes */ int x=5; // Anything after "//" is ignored void other_unused_function(); /*----Section 3: Function Definitions ---*/ void other_unused_function() { cout << "No one uses me!" << endl; } int main(int argc, char *argv[]) { // anything inside these brackets is // part of the main function int y; // a variable declaration stmt y = x+1; // an assignment stmt cout << y << endl; return 0; }
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Executable Binary Image ("test")
1110 0010 0101 1001 0110 1011 0000 1100 0100 1101 0111 1111 1010 1100 0010 1011 0001 0110 0011 1000
C++ file(s) (test.cpp) Compiler
#include <iostream> using namespace std; int main() { int x = 5; cout << "Hello" << endl; cout << "x=" << x; return 0; }
g++ Load & Execute
$ gedit test.cpp & $ gedit test.cpp & $ g++ –g –Wall –o test test.cpp
$ make test $ gedit test.cpp & $ g++ –g –Wall –o test test.cpp $ ./test
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Compile & fix compiler errors
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Edit & write code
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Load & run the executable program
Std C++ & Other Libraries
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Executable Binary Image (test)
1110 0010 0101 1001 0110 1011 0000 1100 0100 1101 0111 1111 1010 1100 0010 1011 0001 0110 0011 1000
C++ file(s) (test.cpp) Compiler
#include <iostream> using namespace std; int main() { int x = 5; cout << "Hello" << endl; cout << "x=" << x; return 0; }
g++ Load & Execute
$ gedit test.cpp & $ gedit test.cpp & $ g++ –g –Wall –o test test.cpp
$ make test $ gedit test.cpp & $ g++ –g –Wall –o test test.cpp $ ./test
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Compile & fix compiler errors
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Edit & write code
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Load & run the executable program
Std C++ & Other Libraries
Fix run-time errors w/ a debugger Fix compile- time errors w/ a debugger