//10.1
#include<stdio.h>
#define MONTHS 12
int main(void)
{
int days[MONTHS] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int index;
for (index = 0; index < MONTHS; index++)
printf("Month %2d has %2d days.\n", index + 1, days[index]);
return 0;
}
//10.2
#include<stdio.h>
#define SIZE 4
int main(void)
{
int no_data[SIZE];
int i;
printf("%2s%14s\n", "i","no_data[i]");
for (i = 0; i < SIZE; i++)
printf("%2d%14d\n", i, no_data[i]);
return 0;
}
//10.3
#include<stdio.h>
#define SIZE 4
int main(void)
{
int some_data[SIZE] = { 1492, 1066 };
int i;
printf("%2s%14s\n", "i", "some_data[i]");
for (i = 0; i< SIZE; i++)
printf("%2d%14d\n", i, some_data[i]);
return 0;
}
//10.4
#include<stdio.h>
int main(void)
{
const int days[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31};
int index;
for (index = 0; index < sizeof days / sizeof days[0]; index++)
printf("Month %2d has %d days.\n", index + 1, days[index]);
return 0;
}
//10.5
#include<stdio.h>
#define MONTHS 12
int main(void)
{
int days[MONTHS] = { 31, 28, [4] = 31, 30, 31, [1] = 29 };
int i;
for (i = 0; i < MONTHS; i++)
printf("%2d %d\n", i + 1, days[i]);
return 0;
}
//10.6
#include<stdio.h>
#define SIZE 4
int main(void)
{
int value1 = 44;
int arr[SIZE];
int value2 = 88;
int i;
printf("value1 = %d, value2 = %d\n", value1, value2);
for (i = -1; i <= SIZE; i++)
arr[i] = 2 * i + 1;
for (i = -1; i < 7; i++)
printf("%2d %d\n", i, arr[i]);
printf("value1 = %d, value2 = %d\n",value1, value2);
printf("address of arr[-1]: %p\n", &arr[-1]);
printf("address of arr[4]: %p\n", &arr[4]);
printf("address of value1: %p\n", &value1);
printf("address of value2 : %p\n", &value2);
return 0;
}
//10.7
#include<stdio.h>
#define MONTHS 12
#define YEARS 5
int main(void)
{
const float rain[YEARS][MONTHS] =
{
{ 4.3, 4.3, 4.3, 3.0, 2.0, 1.2, 0.2, 0.2, 0.4, 2.4, 3.5, 6.6 },
{ 8.5, 8.2, 1.2, 1.6, 2.4, 0.0, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3 },
{ 9.1, 8.5, 6.7, 4.3, 2.1, 0.8, 0.2, 0.2, 1.1, 2.3, 6.1, 8.4 },
{ 7.2, 9.9, 8.4, 3.3, 1.2, 0.8, 0.4, 0.0, 0.6, 1.7, 4.3, 6.2 },
{ 7.6, 5.6, 3.8, 2.8, 3.8, 0.2, 0.0, 0.0, 0.0, 1.3, 2.6, 5.2 },
};
int year, month;
float subtot, total;
printf(" YEAR RAINFALL (inches)\n");
for (year = 0, total = 0; year < YEARS; year++)
{
for (month = 0, subtot = 0; month < MONTHS; month++)
subtot += rain[year][month];
printf("%5d %15.1f\n", 2010 + year, subtot);
total += subtot;
}
printf("\nThe yearly average is %.1f inches.\n\n", total / YEARS);
printf("MONTHLY AVERAGES:\n\n");
printf(" Jan Feb Mar Apr May Jun Jul Aug Sep Oct ");
printf(" Nov Dec\n");
for (month = 0; month < MONTHS; month++)
{
for (year = 0, subtot = 0; year < YEARS; year++)
subtot += rain[year][month];
printf("%4.1f ",subtot / YEARS);
}
printf("\n");
return 0;
}
//10.8
#include<stdio.h>
#define SIZE 4
int main(void)
{
short dates[SIZE];
short * pti;
short index;
double bills[SIZE];
double * ptf;
pti = dates;
ptf = bills;
printf("%23s %15s\n", "short","double");
for (index = 0; index < SIZE; index++)
printf("pointers + %d: %10p %10p\n", index, pti + index, ptf + index);
return 0;
}
//10.9
#include<stdio.h>
#define MONTHS 12
int main(void)
{
int days[MONTHS] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
int index;
for (index = 0; index < MONTHS; index++)
printf("Month %2d has %d days.\n", index + 1,
*(days + index));
return 0;
}
//10.10
#include<stdio.h>
#define SIZE 10
int sun(int ar[], int n);
int main(void)
{
int marbles[SIZE] = { 20, 10, 5, 39, 4, 16, 19, 26, 31, 20 };
long answer;
answer = sum(marbles, SIZE);
printf("The total number of marbles is %ld.\n", answer);
printf("The size of marbles is %zd bytes.\n",
sizeof marbles);
return 0;
}
int sum(int ar[], int n)
{
int i;
int total = 0;
for (i = 0; i < n; i++)
total += ar[i];
printf("The size of ar is %zd bytes.\n", sizeof ar);
return total;
}
//10.11
#include<stdio.h>
#define SIZE 10
int sump(int * start, int * end);
int main(void)
{
int marbles[SIZE] = { 20, 10, 5, 39, 4, 16, 19, 26, 31, 20 };
long answer;
answer = sump(marbles, marbles + SIZE);
printf("The total number of marbles is %ld.\n",answer);
return 0;
}
int sump(int * start, int * end)
{
int total = 0;
while (start < end)
{
total += *start;
start++;
}
return total;
}
//10.12
#include<stdio.h>
int data[2] = { 100, 200 };
int moredata[2] = { 300, 400 };
int main(void)
{
int * p1, *p2, *p3;
p1 = p2 = data;
p3 = moredata;
printf(" *p1 = %d, *p2 = %d, *p3 = %d\n",*p1, *p2, *p3);
printf("*p1++ = %d, *++p2 = %d, (*p3)++ = %d\n",*p1++, *++p2, (*p3)++);
printf(" *p1 = %d, *p = %d, *p3 = %d\n",*p1, *p2, *p3);
return 0;
}
//10.13
#include<stdio.h>
int main(void)
{
int urn[5] = { 100, 200, 300, 400, 500 };
int * ptr1, *ptr2, *ptr3;
ptr1 = urn;
ptr2 = &urn[2];
printf("pointer value, dereferenced pointer, pointer address:\n");
printf("ptr1 = %p, *ptr1 = %d, &ptr1 = %p\n", ptr1, *ptr1, &ptr1);
ptr3 = ptr1 + 4;
printf("\nadding an int to a pointer:\n");
printf("ptr1 + 4 = %p, *(ptr1 + 4) = %d\n", ptr1 + 4, *(ptr1 + 4));
ptr1++;
printf("\nvalue after ptr1++:\n");
printf("ptr1 = %p, *ptr1 = %d, &ptr1 = %p\n", ptr1, *ptr1, &ptr1);
ptr2--;
printf("\nvalues after --ptr2:\n");
printf("ptr2 = %p, *ptr2 = %d, &ptr2 = %p\n", ptr2, *ptr2, &ptr2);
--ptr1;
++ptr2;
printf("\nPointers reset to original values:\n");
printf("ptr1 = %p, ptr2 = %p\n", ptr1, ptr2);
printf("\nsubtracting one pointer from another:\n");
printf("ptr2 = %p, ptr1 = %p, ptr2 - ptr1 = %td\n",ptr2, ptr1, ptr2 - ptr1);
printf("\nsubtracting an int from a pointer:\n");
printf("ptr3 = %p, ptr3 - 2 = %p\n", ptr3, ptr3 - 2);
return 0;
}
//10.15
#include<stdio.h>
#define SIZE 5
void show_array(const double ar[], int n);
void mult_array(double ar[], int n, double mult);
int main(void)
{
double dip[SIZE] = { 20.0, 17.66, 8.2, 15.3, 22.22 };
printf("The original dip array:\n");
show_array(dip, SIZE);
mult_array(dip, SIZE, 2.5);
printf("The aip array after calling mult_array():\n");
show_array(dip, SIZE);
return 0;
}
void show_array(const double ar[], int n)
{
int i;
for (i = 0; i < n; i++)
printf("%8.3f ",ar[i]);
putchar('\n');
}
void mult_array(double ar[], int n, double mult)
{
int i;
for (i = 0; i < n; i++)
ar[i] *= mult;
}
//10.16
#include<stdio.h>
int main(void)
{
int zippo[4][2] = { { 2, 4 }, { 6, 8 }, { 1, 3 }, { 5, 7 } };
int (*pz)[2];
pz = zippo;
printf(" pz = %p, pz + 1 = %p\n", pz, pz + 1);
printf("pz[0] = %p, pz[0] + 1 = %p\n",pz[0], pz[0] + 1);
printf(" *pz = %p, *pz + 1 = %p\n", *pz, *pz + 1);
printf("pz[0][0] = %d\n", pz[0][0]);
printf(" *pz[0] = %d\n", *pz[0]);
printf(" **pz = %d\n", **pz);
printf(" pz[2][1] = %d\n", pz[2][1]);
printf("*(*(pz+2) + 1) = %d\n", *(*(pz + 2) + 1));
return 0;
}
//10.17
#include<stdio.h>
#define ROWS 3
#define COLS 4
void sum_rows(int ar[][COLS], int rows);
void sum_cols(int [][COLS], int);
int sum2d(int (*ar)[COLS], int rows);
int main(void)
{
int junk[ROWS][COLS] = {
{ 2, 4, 6, 8 },
{ 3, 5, 7, 9 },
{ 12, 10, 8, 6 }
};
sum_rows(junk, ROWS);
sum_cols(junk, ROWS);
printf("Sum of all elements = %d\n", sum2d(junk, ROWS));//不知道爲什麼這句話輸出不了
return 0;
}
void sum_rows(int ar[][COLS], int rows)
{
int r;
int c;
int tot;
for (r = 0; r < rows; r++)
{
tot = 0;
for (c = 0; c < COLS; c++)
tot += ar[r][c];
printf("row %d: sum = %d\n", r, tot);
}
}
void sum_cols(int ar[][COLS], int rows)
{
int r;
int c;
int tot;
for (c = 0; c < COLS; c++)
{
tot = 0;
for (r = 0; r < rows; r++)
tot += ar[r][c];
printf("col %d: sum = %d\n", c, tot);
}
}
int sum2d(int ar[][COLS], int rows)
{
int r;
int c;
int tot = 0;
for (r = 0; r < COLS; c++)
for (c = 0; c < COLS; c++)
tot += ar[r][c];
return tot;
}
//10.18
#include<stdio.h>
#define ROWS 3
#define COLS 4
int sum2d(int rows, int cols, int ar[rows][cols]);
int main(void)
{
int i, j;
int rs = 3;
int cs = 10;
int junk[ROWS][COLS] = {
{ 2, 4, 6, 8 },
{ 3, 5, 7, 9 },
{ 12, 10, 8, 6 }
};
int morejunk[ROWS - 1][COLS + 2] = {
{ 20, 30, 40, 50, 60, 70 },
{ 5, 6, 7, 8, 9, 10 }
};
int varr[rs][cs];
for (i = 0; i < rs; i++)
for (j = 0; j < cs; j++)
varr[i][j] = i * j + j;
printf("3x5 array\n");
printf("Sum of all elements = %d\n", sum2d(ROWS, COLS, junk));
printf("2x6 array\n");
printf("Sum of all elements = %d\n", sum2d(ROWS - 1, COLS + 2, morejunk));
printf("3x10 VLA\n");
printf("Sum of all elements = %d\n", sum2d(rs, cs, varr));
return 0;
}
//帶變長數組形參的函數
int sum2d(int rows, int cols, int ar[rows][cols])
{
int r;
int c;
int tot = 0;
for (r = 0; r < rows; r++)
for (c = 0; c < cols; c++)
tot += ar[r][c];
return tot;
}
//10.19
#include<stdio.h>
#define COLS 4
int sum2d(const int ar[][COLS], int rows);
int sum(const int ar[], int n);
int main(void)
{
int total1, total2, total3;
int * pt1;
int (*pt2)[COLS];
pt1 = (int[2]) { 10, 20 };
pt2 = (int[2][COLS]) { { 1, 2, 3, -9 }, { 4, 5, 6, -8 } };
total1 = sum(pt1, 2);
total2 = sum2d(pt2, 2);
total3 = sum((int []) { 4, 4, 4, 5, 5, 5}, 6);
printf("total1 = %d\n", total1);
printf("total2 = %d\n", total2);
printf("total3 = %d\n", total3);
return 0;
}
int sum(const int ar[], int n)
{
int i;
int total = 0;
for (i = 0; i < n; i++)
total += ar[i];
return total;
}
int sum2d(const int ar[][COLS], int rows)
{
int r;
int c;
int tot = 0;
for (r = 0; r < rows; r++)
for(c = 0; c < COLS; c++)
tot += ar[r][c];
return tot;
}
