Embed Size (px)
Citation preview
Young Won Lim11/13/17
Example 3
Young Won Lim11/13/17
Copyright (c) 2010 - 2017 Young W. Lim.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".
Please send corrections (or suggestions) to [email protected].
This document was produced by using OpenOffice.
Example 3 3 Young Won Lim11/13/17
Using Struct
#include <stdio.h>#include <stdlib.h>#define SIZE 10
struct Stype { int I; int K; int E; int M; double A;};
Example 3 4 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Calculating the average of three numbers//--------------------------------------------------double avg3(int x, int y, int z){ return (x+y+z) / 3.;}
Example 3 5 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Initialize S[SIZE] arrays// by assigning random number grade//--------------------------------------------------void init_arrays (struct Stype T[]){ int i;
// srand(7) makes rand() generate // the same random sequence // --> easy to debug a program srand(7);
for (i=0; i<SIZE; ++i) { T[i].I = i+1 + 201600; // I T[i].K = rand() % 101; // K T[i].E = rand() % 101; // E T[i].M = rand() % 101; // M T[i].A = avg3(T[i].K, T[i].E, T[i].M); }}
Example 3 6 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Print the original table//-------------------------------------------------void pr_table (struct Stype T[]){ int i;
printf("%10s %10s %10s %10s %10s \n", "StID", "Korean", "Enlgish", "Math", "Average");
for (i=0; i<SIZE; ++i) { printf("%10d %10d %10d %10d %10.2f \n", T[i].I, T[i].K, T[i].E, T[i].M, T[i].A);
}}
Example 3 7 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Bubble Sort Double Array//-------------------------------------------------void DbubbleSort(double a[], int size){ int p, j; double tmp;
for (p=1; p< size; ++p) { for (j=0; j< size-1; ++j) { if ( a[j] < a[j+1] ) { tmp = a[j]; a[j] = a[j+1]; a[j+1] = tmp; } } }}
Example 3 8 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Print the Sorted Table//-------------------------------------------------void pr_sorted_table (struct Stype T[]){ int i, j; double B[SIZE]; // Backup Array for Sorting
for (i=0; i<SIZE; ++i) B[i] = T[i].A;
//.................... DbubbleSort(B, SIZE); //....................
printf("\n\nSorted on a student's average\n\n"); printf("%10s %10s %10s %10s %10s \n", "StID", "Korean", "Enlgish", "Math", "Average");
for (i=0; i<SIZE; ++i) { for (j=0; j<SIZE; ++j) if (B[i] == T[j].A) break;
printf("%10d %10d %10d %10d %10.2f \n", T[j].I, T[j].K, T[j].E, T[j].M, T[j].A); }
Example 3 9 Young Won Lim11/13/17
Using Struct
j = SIZE / 2; printf("\n"); printf("The median index of the sorted array: %d \n", j); printf("The median of the averarge: %10.2f\n", B[j]); printf("Another possible median index: %d\n", j-1); printf("The corresponding median : %10.2f\n", B[j-1]); printf("\n");
}
Example 3 10 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Average over Integer Array//-------------------------------------------------double Avg(struct Stype T[], int n) { int i; double S=0.0;
// n is used to select // Korean (n=0) // English (n=1) // Math (n=2) // Avg (n=3)
for (i=0; i<SIZE; ++i) { switch (n) { case 0 : S += T[i].K; break; case 1 : S += T[i].E; break; case 2 : S += T[i].M; break; case 3 : S += T[i].A; break; defalut: S = 0; break; } } return S/SIZE;}
Example 3 11 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Average over Doubl Array//-------------------------------------------------// double DAvg(double N[], int n) {// int i; double S=0.0;//// for (i=0; i<n; ++i) S+= N[i];// return S/n;// }
Example 3 12 Young Won Lim11/13/17
Using Struct
//--------------------------------------------------// Print the Averages//-------------------------------------------------void pr_averages(struct Stype T[]) { double A1 = Avg(T, 0); // 0 for Korean double A2 = Avg(T, 1); // 1 for English double A3 = Avg(T, 2); // 2 for Math double A4 = Avg(T, 3); // 3 for Averages
printf("%10s %10.2f %10.2f %10.2f %10.2f \n", "Average", A1, A2, A3, A4);}
Example 3 13 Young Won Lim11/13/17
Using Struct
//====================================================// main//====================================================int main(void) {
// S[i].I --> I[i] // ID of a student // S[i].K --> K[i] // Grade of Korean // S[i].E --> E[i] // Grade of English // S[i].M --> M[i] // Grade of Math // S[i].A --> A[i] // a student's Average
struct Stype S[SIZE];
// S is the array name // S is also the address like pointer variables // thus, the following calls are pass-by-reference init_arrays(S); pr_table(S); pr_sorted_table(S); pr_averages(S);
}
Example 3 14 Young Won Lim11/13/17
Using Struct
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
Example 3 15 Young Won Lim11/13/17
Using Struct
Example 3 16 Young Won Lim11/13/17
init_arrays() - filling grades
7686
4498
97
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
Random Number
Example 3 17 Young Won Lim11/13/17
avg3()avg3()avg3()avg3()avg3()avg3()avg3()avg3()
init_arrays() - computing averages
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
i+1 + 201600
Example 3 18 Young Won Lim11/13/17
pr_table()
I K E M A
Student ID Korean English Math Average
i
Example 3 19 Young Won Lim11/13/17
A[0]A[1]A[2]A[3]A[4]A[5]A[6]A[7]
pr_sorted_table – copying A to B
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
B[0]B[1]B[2]B[3]B[4]B[5]B[6]B[7]
B
Average2
First, copy A[i] into B[i]
Example 3 20 Young Won Lim11/13/17
pr_sorted_table – sorting B
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
B[0]B[1]B[2]B[3]B[4]B[5]B[6]B[7]
B
Average2
after DbubbleSort()B[i] > B[i]
A, B: different order
Example 3 21 Young Won Lim11/13/17
A[0]A[1]
pr_sorted_table – printing by B
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
B[0]B[1]B[2]B[3]B[4]B[5]B[6]B[7]
B
Average2
Search A[j] = B[i]
Example 3 22 Young Won Lim11/13/17
pr_averages
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
B[0]B[1]B[2]B[3]B[4]B[5]B[6]B[7]
B
Average2
Search A[j] = B[i]
Avg() Avg()Avg() Avg()
Example 3 23 Young Won Lim11/13/17
Using Struct
double avg3 (int x, int y, int z);void init_arrays (struct Stype T[]);void pr_table (struct Stype T[]);void DbubbleSort (double a[], int size);void pr_sorted_table (struct Stype T[]);double Avg (struct Stype T[], int n);void pr_averages (struct Stype T[]);
init_arrays(S); T[i].A = avg3(T[i].K, T[i].E, T[i].M);
pr_table(S);
pr_sorted_table(S); DbubbleSort(B, SIZE);
pr_averages(S); double A1 = Avg(T, 0); // 0 for Korean double A2 = Avg(T, 1); // 1 for English double A3 = Avg(T, 2); // 2 for Math double A4 = Avg(T, 3); // 3 for Averages
Example 3 24 Young Won Lim11/13/17
Using Struct
//====================================================// main//====================================================int main(void) {
// S[i].I --> I[i] // ID of a student // S[i].K --> K[i] // Grade of Korean // S[i].E --> E[i] // Grade of English // S[i].M --> M[i] // Grade of Math // S[i].A --> A[i] // a student's Average
struct Stype S[SIZE];
// S is the array name // S is also the address like pointer variables // thus, the following calls are pass-by-reference init_arrays(S); pr_table(S); pr_sorted_table(S); pr_averages(S);
}
Example 3 25 Young Won Lim11/13/17
init_arrays() - computing averages
Student ID Korean English Math Average
S[0]S[1]S[2]S[3]S[4]S[5]S[6]S[7]
S[i].I S[i].K S[i].E S[i].M S[i].A
i
struct Stype T[]
T
Young Won Lim11/13/17
References
[1] Essential C, Nick Parlante[2] Efficient C Programming, Mark A. Weiss[3] C A Reference Manual, Samuel P. Harbison & Guy L. Steele Jr.[4] C Language Express, I. K. Chun[5] cprogramex.wordpress.com
![2017-02-18 function(int a, int b, int c) {char buffer1[8]; char buffer2[12];} int main() {function(1,2,3);} Example program Function parameters Return address Saved frame pointer Local](https://img.dokumen.tips/doc/110x75/5aba5fc37f8b9a567c8b6fd1/2017-02-18-functionint-a-int-b-int-c-char-buffer18-char-buffer212-int.jpg)
![* example program to demonstrate the passing of an array */ #include int maximum( int [] ); /* ANSI function prototype */ int maximum(](https://img.dokumen.tips/doc/110x75/5697c0261a28abf838cd5be3/-example-program-to-demonstrate-the-passing-of-an-array-include-int-maximum.jpg)
