#include <stdio.h>
#define MAXLINE 1000 /*maximum input line size */
int getline(char line[], int maxline);
void copy(char to[], char from[]);
/*print longest input line */
int main(){
int len; /*current line length */
int max; /*maximum length seen so far */
char line[MAXLINE]; /*longest line save here */
max = 0;
while((len = getline(line, MAXLINE)) > 0){
printf("%d , %s", len, line);
if (len > max){
max = len;
copy(longest, line);
}
}
if(max > 0) /* there was a line */
printf("%s", longest);
return 0;
}
/*getline: read a line into s, return length */
int getline(char s[], int lim)
{
int c, i, j;
j =0;
for(i =0; (c =getchar()) != EOF && c != '\n'; ++i)
if (i < lim -2){
s[j] = c; /* line still in boundaries */
++j;
}
if (c == '\n'){
s[j] = c;
++j;
++i;
}
s[j] = '\0';
return i;
}
/*copy: copy 'from' into 'to'; */
void copy(char to[], char from[])
{
int i;
i =0;
while((to[i] = from[i]) != '\0')
++i;
}Author: curious_cat
Write a temp conversion program that uses a function
#include <stdio.h>
float celsius(float fahr);
/*print Fahrenheit - Celsius table
for fahr = 0, 20, ......., 300; floating-point version
*/
int main(){
float fahr;
int lower, upper, step;
lower =0; /*lower limit of temperature */
upper = 300; /*upper limit */
step = 20; /*step size */
fahr = lower;
while (fahr <= upper){
printf("%3.0f %6.1f\n", fahr, celsius(fahr));
fahr = fahr + step;
}
}
/*celsius: convert fahr into celsius */
float celsius(float fahr){
return (5.0 / 9.0) * (fahr - 32.0);
}Write a program to print a histogram of the frequencies of different characters in its input.
#include <stdio.h>
#include <ctype.h>
#define MAXHIST 15 /* max length of histogram */
#define MAXCHAR 128 /*max different characters */
/*print horizontal histogram freq. of different characters */
int main(){
int c, i;
int len; /* length of each bar */
int maxvalue; /* maximum value for cc[] */
int cc[MAXCHAR]; /* character counters */
for (i=0 ;i <MAXCHAR; ++i)
cc[i] = 0;
while ((c =getchar()) != EOF)
if (c < MAXCHAR)
++cc[c];
maxvalue = 0;
for( i = 1; i < MAXCHAR; ++i){
if(isprint(i))
printf(" %5d - %c - %5d : ", i, i, cc[i]);
else
printf(%5d - - %5d : ", i, cc[i])
if (cc[i] > 0){
if ((len = cc[i] * MAXHIST / maxvalue) <= 0)
len = 1;
}else
len = 0;
while (len > 0){
putchar(' *');
--len;
}
putchar('\n');
}
}write a program to print a histogram of the lengths of words in its input.It is easy to draw the histogram with the bars horizontal;a vertical orientation is more challenging.
#include <stdio.h>
#define MAXHIST 15 /*max length of histogram */
#define MAXWORD 11 /*max length of a word */
#define IN 1 /*inside a word */
#define OUT 0 /*outside a word */
/*print a horizontal histogram */
int main(){
int c, i, nc, state;
int len; /*length of each bar */
int maxvalue; /*maximum value for wl[] */
int ovflow; /*number of overflow words */
int wl[MAXWORD]; /*word length counters */
state =OUT;
nc = 0; /*number of chars in a word */
ovflow =0 /*number of words >= MAXWORDS*/
for(i =0; i <MAXWORD; ++i)
wl[i] = 0;
while((c =getchar()) != EOF){
if (c == ' ' || c == '\n' || c =='\t'){
state =OUT;
if (nc > 0)
if (nc < MAXWORD)
++wl[nc];
else
++ovflow;
nc = 0;
}else if (state == OUT){
state = IN;
nc = 1; /*beginning of a new word */
}else
++nc; /*inside a word */
}
maxvalue = 0;
for(i = 1; i< MAXWORD; ++i)
if (wl[i] > maxvalue)
maxvalue = wl[i];
for( i = 1; i <MAXWORD; ++i){
printf("%5d - %5d : ", i, wl[i]);
if (wl[i] > 0) {
if ((len = wl[i] = MAXHIST /maxvalue) <= 0)
len = 1;
}else
len = 0;
while(len > 0){
putchar(' * ');
--len;
}
putchar('\n');
}
if (ovflow > 0)
printf("There are %d words >= %d\n", ovflow, MAX\WORD);
}
/*
VERTICAL HISTOGRAM
*/
#include <stdio.h>
#define MAXHIST 15 /*max length of histogram */
#define MAXWORD 11 /*max length of a word */
#define IN 1 /* inside a word */
#define OUT 0 /*outside a word */
/*print vertical histogram */
int main(){
int c, i, j, nc, state;
int maxvalue; /*maximum value for wl[] */
int ovflow; /*number of overflow words */
int wl[MAXWORD]; /*word length counters */
state = OUT;
nc = 0; /*number of chars in a word */
ovflow = 0; /*number of words >= MAXWORD */
for (i = 0; i < MAXWORD; ++i)
wl[i] = OUT;
while ((c = getchar()) != EOF) {
if (c == ' ' || c == '\n' || c == '\t'){
state =OUT;
if (nc > 0)
if (nc < MAXWORD)
++wl[nc];
else
++ovflow;
nc = 0;
}else if (state == OUT) {
state = IN;
nc = 1; /*beginning of a new word */
}else
++nc; /*inside a word */
}
maxvalue = 0;
for(i = 1; i< MAXWORD; ++i)
if (wl[i] > maxvalue)
maxvalue = wl[i];
for (i = MAXHIST; i > 0; --i){
for (j = 1; j < MAXWORD; ++j)
if (wl[j] = MAXHIST /maxvalue >= i)
printf(" *");
else
printf(" ");
putchar('\n');
}
for (i = 1; i <MAXWORD; ++i)
printf("%4d", i);
putchar('\n')
for(i = 1; i <MAXWORD; ++i)
printf("%4d ", wl[i]);
putchar('\n');
if (ovflow > 0)
printf("There are %d words >= %d\n", ovflow, MAXWORD);
}Write a program that prints its input one word per line.
#include <stdio.h>
#define IN 1 /*inside a word */
#define OUT 0 /*outside a word */
/*print input one word per line */
int main(){
int c, state;
state =OUT;
while ((c =getchar()) != EOF){
if (c == ' ' || c == '\n' || c == '\t'){
if(state == IN ){
putchar('\n');
state = OUT;
}
}else if (state == OUT){
state =IN; /*beginning of word */
putchar(c);
}else /*inside a word */
putchar(c);
}
}Write a program to copy its input to its output, replacing each tab by \t, each backspace by \b, and each backslash by \\.This makes tabs and backspaces visible in unambiguous.
#include<stdio.h>
/*replace tabs and backspaces with visible characters */
int main(){
int c;
while((c =getchar()) != EOF){
if (c == '\t')
printf("\\t");
else if (c == '\b')
printf("\\b");
else if (c != '\\')
printf("\\\\");
else
putchar(c);
}
}write a program to copy its input to its output, replace each string of one or more blanks by a single blank.
#include <stdio.h>
#define NONBLANK 'a'
/*replace string of blanks with a single blank */
int main(void){
int c, lastc;
lastc =NONBLANK;
while ((c =getchar()) != EOF){
if (c != ' ')
putchar(c);
if (c == ' ')
if(lastc != ' ')
putchar(c);
lastc = c;
}
}Verify that the expression getchar() != EOF is 0 or 1
#include <stdio.h>
main()
{
int c;
while (c =getchar() != EOF)
printf("%d\n", c);
printf("%d - at EOF\n", c);
}Convert word description to declaration.
/*undcl: convert word description to declaration */
main() {
int type;
char temp[MAXTOKEN];
while (gettoken() != EOF){
strcpy(out, token);
while((type =gettoken()) != '\n')
if (type == PARENS || type == BRACKETS)
strcat(out, token);
else if (type == '*') {
sprintf(temp, "(*%s)", out);
strcpy(out, temp);
} else if(type == NAME){
sprintf(temp, "%s %s", token ,out);
strcpy(out, temp);
}else
printf("invalid input at %s\n", token);
printf("%s\n", out);
}
return 0;
}dcl: parse a declarator
#include<stdio.h>
#include <string.h>
#include<ctype.h>
#define MAXTOKEN 100
enum {NAME, PARENS, BRACKETS};
void dcl(void);
void dirdcl(void);
int gettoken(void);
int tokentype; /*type of last token */
char token[MAXTOKEN]; /*last token string */
char name[MAXTOKEN]; /*identifier name */
char datatype[MAXTOKEN]; /*data type = char, int, etc, */
char out[1000]; /* output string */
main(){ /* convert declaration to words */
while(gettoken() != EOF){ /* 1st token on line */
strcpy(datatype, token); /* is the datatype */
out[0] = '\0';
dcl(); /* parse rest of line */
if (tokentype != '\n')
printf("syntax error\n");
printf("%s: %s %s\n", name, out, datatype);
}
return 0;
}
int gettoken(void) {/* return next token */
int c, getch(void);
void ungetch(int);
char *p =token;
while ((c =getch()) == ' ' || c =='\t')
;
if (c == '(') {
if ((c =getch()) == ')' ) {
strcpy(token, "()");
return tokentype = PARENS;
}else {
ungetch(c);
return tokentype = '(';
}
}else if (c == '[' ) {
for (*p++ =c; (*p++ = getch()) != ']';)
;
*p = '\0';
return tokentype = BRACKETS;
} else if (isalpha(c)) {
for (*p++ = c; isalnum(c = getch()); )
*p++ = c;
*p = '\0';
ungetch(c);
return tokentype = NAME;
} else
return tokentype = c;
}
/*dcl: parse a declarator */
void dcl(void){
int ns;
for (ns = 0; gettoken() == '*';) /* count *'s */
ns++;
dirdcl();
while (ns-- > 0)
strcat(out, " pointer to ");
}
/*dirdcl: parse a direct declarator */
void dirdcl(void){
int type;
if (tokentype == '('){ /* (dcl) */
dcl();
if (tokentype != ')')
printf("error: missing )\n");
} else if (tokentype == NAME) /* variable name */
strcpy(name, token);
else
printf("error: expected name or (dcl)\n");
while ((type == PARENS)
strcat(out, " array");
strcat(out, token);
strcat(out, "of"):
}
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