I'm trying to "scroll" through a list of names I got the scroll down part right but I can't figure out how to go backwards (scroll up). I The error lies in the i + j -1, but I just cant get the right output without a segmentation fault. This is because I'm trying to access a negative number I'm assuming.
int i,list,j = 1;
char answer [5];
do {
if (strcmp(answer, "+") == 0) {
printf("Number of Contacts = %d\n", count);
for(i=1;i<6;i++) {
if ((i + j) - 1 == count) {
printf("end of list\n");
break;
} else {
list = i + j;
if(strcmp(contactData[(i+j)-1].company_name," ") == 0) {
printf("%d.\t%s %s\n", list, contactData[(i+j)-1].first_name, contactData[(i+j)-1].last_name);
} else {
printf("%d.\t%s\n", list, contactData[(i+j)-1].company_name);
}
}
}
}
if (strcmp(answer, "-") == 0) {
printf("Number of Contacts = %d\n", count);
for(i=1;i<6;i++) {
if ((i + j - 1) < 0) {
printf("end of list\n");
break;
} else {
list = j - i;
if(strcmp(contactData[(j-i)-1].company_name," ") == 0) {
printf("%d.\t%s %s\n", list, contactData[(j-i)-1].first_name, contactData[(j-i)-1].last_name);
} else {
printf("%d.\t%s\n", list, contactData[(j-i)-1].company_name);
}
}
}
}
printf("Action(+,-,#,A,X):");
scanf("%s", answer);
getchar();
j++;
} while (1)
This is my output:
Number of Contacts = 14
1. Chiraq
2. Cobra
3. Andre D'Souza
4. Gucci
5. Jordan
Action(+,-,#,A,X):+
Number of Contacts = 14
2. Cobra
3. Andre D'Souza
4. Gucci
5. Jordan
6. Migos
Action(+,-,#,A,X):+
Number of Contacts = 14
3. Andre D'Souza
4. Gucci
5. Jordan
6. Migos
7. North Face
If your contactData array starts at [0] and ends at [count-1] this example could work for you.
int i,list,j = 0;
char answer [5];
do {
printf("Number of Contacts = %d\n", count);
for(i=0;i<6;i++) {
list = i+j;
if (list >= count) {
printf("end of list\n");
break;
}
if(strcmp(contactData[list].company_name," ") == 0) {
printf("%d.\t%s %s\n", list+1, contactData[(list].first_name, contactData[list].last_name);
} else {
printf("%d.\t%s\n", list+1, contactData[(list].company_name);
}
}
printf("Action(+,-,#,A,X):");
scanf("%s", answer);
if(strcmp(answer, "+") == 0) {
if((j+1)<count) j++;
}
else if(strcmp(answer, "-") == 0) {
if(j>0) j--;
}
} while (1);
Related
Every time I try and run only the first loop runs. It ask how many items were sold and then just stops running. I'm not really sure what I did wrong. If anyone has any tips that would be great(story if there's some formatting issues, SO wouldn't let me post the question without them).
Everything else looks fine but if any other improvements could be made please let me know.
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
int digit(char term[])
{
int i = 0;
int val = 0;
while (term[i] != '\0')
{
val = val * 10 + term[i] - '0';
i++;
}
return val;
}
void error()
{
printf("Error: Sales figures must be numbers.\n");
printf("Please try again.\n");
}
bool isnumber(char term[])
{
int i = 0;
while (term[i])
{
if( isdigit(term[i]) == 0)
{
return false;
i++;
}
}
return true;
}
int main()
{
int sales[3][2], costs[3] = {3, 4, 1}, weekends[2] = {0, 0};
int i, j, val;
char term[100];
while (1)
{
printf("Number of Bagel sales on Saturday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error;
}
else
{
sales[0][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Flatbread sales on Saturday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error;
}
else
{
sales[1][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Muffin sales on Saturday: ");
scanf("%s", term);
if (isnumber(term) == false)
{
error;
}
else
{
sales[2][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Bagel sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error;
}
else
{
sales[0][1] = digit(term);
break;
}
}
while (1)
{
printf("Number of Flatbread sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error;
}
else
{
sales[1][1] = digit(term);
break;
}
}
while (1)
{
printf("Number of Muffin sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error;
}
else
{
sales[2][1] = digit(term);
break;
}
}
for (i = 0; i < 2, i++;)
{
for (j = 0; j < 3, j++;)
{
weekends[i] += costs[j] * sales[i][j];
}
}
printf("\n");
for (i = 0; i < 3, i++;)
{
printf("%d", costs[i]);
}
printf(".");
for (i = 0; i < 3, i++;)
{
for (j = 0; j < 2, j++;)
{
printf("%d", sales[i][j]);
}
if (i == 0)
{
printf(" = ");
printf("%d %d", weekends[0], weekends[1]);
}
printf("\n ");
}
printf("\nTotal sales on Saturday: $%d", weekends[0]);
printf("\nTotal sales on Sunday: $%d", weekends[1]);
printf("\nTotal sales over the weekend: $%d", weekends[0] + weekends[1]);
return 0;
}
You have an infinite loop in isnumber(). It will return false if the first character is not a digit. But if the first character is a digit, it never increments i, so it keeps testing the first character repeatedly.
i++ should not be in the if statement.
bool isnumber(char term[])
{
int i = 0;
while (term[i])
{
if(!isdigit(term[i]))
{
return false;
}
i++;
}
return true;
}
And as others have pointed out, you need to put () after error to call it.
As for your programming stopping; you use isdigit on line 30 without declaring it.
Along that, you use error everywhere without invoking it. Use error() to invoke the function and print the error-information.
Just a small formatting tip as well: instead of if (something == false) use if (!something)
Your use of error; is incorrect. You should write error(); instead.
When I go to print the output of the program everything shows up as zero. I think the variable aren't storing themselves, but I'm not totally sure. When I go to look over everything, it looks right but clearly isn't. Any help would be really appreciated. Sorry if the formatting seems a little off, Stack Overflow wouldn't accept it otherwise.
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
int digit(char term[])
{
int i = 0;
int val = 0;
while (term[i] != '\0')
{
val = val * 10 + term[i] - '0';
}
i++;
return val;
}
void error()
{
printf("Error: Sales figures must be numbers.\n");
printf("Please try again.\n");
}
bool isnumber(char term[])
{
int i = 0;
while (term[i])
{
if( isdigit(term[i]) == 0)
{
return false;
i++;
}
}
return true;
}
int main()
{
int sales[3][2], costs[3] = {3, 4, 1}, weekends[2] = {0, 0};
int i, j, val;
char term[100];
while (1)
{
printf("Number of Bagel sales on Saturday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error();
}
else
{
sales[0][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Flatbread sales on Saturday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error();
}
else
{
sales[1][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Muffin sales on Saturday: ");
scanf("%s", term);
if (isnumber(term) == false)
{
error();
}
else
{
sales[2][0] = digit(term);
break;
}
}
while (1)
{
printf("Number of Bagel sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error();
}
else
{
sales[0][1] = digit(term);
break;
}
}
while (1)
{
printf("Number of Flatbread sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error();
}
else
{
sales[1][1] = digit(term);
break;
}
}
while (1)
{
printf("Number of Muffin sales on Sunday: ");
scanf("%s", term);
if( isnumber(term) == false)
{
error();
}
else
{
sales[2][1] = digit(term);
break;
}
}
for (i = 0; i < 2, i++;)
{
for (j = 0; j < 3, j++;)
{
weekends[i] += costs[j] * sales[i][j];
}
}
printf("\n");
for (i = 0; i < 3, i++;)
{
printf("%d", costs[i]);
}
printf(".");
for (i = 0; i < 3, i++;)
{
for (j = 0; j < 2, j++;)
{
printf("%d", sales[i][j]);
}
if (i == 0)
{
printf(" = ");
printf("%d %d", weekends[0], weekends[1]);
}
printf("\n ");
}
printf("\nTotal sales on Saturday: $%d", weekends[0]);
printf("\nTotal sales on Sunday: $%d", weekends[1]);
printf("\nTotal sales over the weekend: $%d", weekends[0] + weekends[1]);
return 0;
}
You are not incrementing i in the loop. Your code for digit is:
int digit(char term[])
{
int i = 0;
int val = 0;
while (term[i] != '\0')
{
val = val * 10 + term[i] - '0';
}
i++; /* ---- this is outside the loop !! */
return val;
}
But it ought to look like:
int
digit(const char *term)
{
int val = 0;
while( *term != '\0' ){
val = val * 10 + *term - '0';
term += 1;
}
return val;
}
When I run my code, the console doesn't output anything. When I go into "debug as c application mode" and step into the makeBoard() method that is supposed to print stuff nothing is shown on the console. I can't work on this project if the console doesn't work.
Whenever I run my code with only makeBoard() in the int main(void) method, the console outputs what it's supposed to. However, when I add the rest of my code in the int main(void) method, nothing is shown in the console window.
I am very new to C and the eclipse IDE. Do I need to download something?
The makeBoard() method:
void makeBoard(){
printf("Row A: ");
for(int i = 0; i< rowAcounter; i++)
{
printf("O");
}
printf("\n");
printf("Row B: ");
for(int i = 0; i< rowBcounter; i++)
{
printf("O");
}
printf("\n");
printf("Row C: ");
for(int i = 0; i< rowCcounter; i++)
{
printf("O");
}
printf("\n");
}
My complete int main method and the rest of my program:
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
void makeBoard();
void nextTurn(int player);
void prompt(int turn);
_Bool isGameOver();
void done(int currentTurn);
void test();
void update();
int rowAcounter = 3;
int rowBcounter = 5;
int rowCcounter = 8;
int currentPlayer = 0; // 0= player 1's turn, 1
= player 2's turn
char firstIn;
char secondIn;
_Bool flag = 0;
int main(void){
makeBoard();
while(isGameOver() == 0){
prompt(currentPlayer);
update();
nextTurn(currentPlayer);
if(flag == 1){
break;
}
makeBoard();
}
done(currentPlayer);
return 0;
}
the rest of my code:
void update(){
poll: scanf(" %c%c", &firstIn, &secondIn);
int checkFirst = firstIn - 'A';
if((checkFirst < 0) || (checkFirst > 2))
{
printf("\n Try again, you ape.");
goto poll;
}
int checkSecond = secondIn - '0';
if((checkSecond < 0 ) || (checkSecond > 8)){
printf("\n Try again, you fricker.");
goto poll;
}
else if(checkFirst == 0){ // the player chose row A
if(checkSecond > 3){
printf("\n Try again, you frick.");
goto poll;
}
else{
rowAcounter = rowAcounter - checkSecond;
}
}
else if(checkFirst == 1){ // the player chose row B
if(checkSecond > 5){
printf("\n Try again, you headass.");
goto poll;
}
else{
rowBcounter = rowBcounter - checkSecond;
}
}
else{ // the player chose row C
if(checkSecond > 8)
{
printf("\n Try again!");
goto poll;
}
else{
rowCcounter = rowCcounter - checkSecond;
}
}
if(isGameOver() == 1){
flag = 1;
}
}
void nextTurn(int player){
if(player == 0){
player = 1;
}else
{
player = 0;
}
}
void prompt(int turn){
if(turn == 0){
printf("Player 1, make your move:");
}
else{
printf("Player 2, make your move:");
}
}
_Bool isGameOver(){
if((rowAcounter == 0) && (rowBcounter == 0) && (rowCcounter == 0)){
return 1;
}
else{
return 0;
}
}
void done(int currentTurn){
if(currentTurn == 0){
puts("Player 1 wins!");
}
else{
puts("Player 2 wins!");
}
}
People in a group are sitting in a group numbered 1 to N. It is known that people of same countries are sitting together.
Output is a single integer denoting no of distinct countries.
Input
4 (no of test cases)
2 (no of people in group)
1 1 ( in this there are 2 people from diff country)
2
1 3
7
1 1 2 2 3 3 3
7
7 7 7 7 7 7 7
Output should be
2
Invalid Data
4
1
My program:please tell me where is the error
#include<stdio.h>
#include<string.h>
int main()
{
int tcaseno,nopgrp,flag=0;
int arr[1000];
int count=0,i=0,j=0,t=0;
scanf("%d", &tcaseno);
t=tcaseno;
while(t>0)
{
scanf("%d\n", &nopgrp);
for (i = 0; i < nopgrp;i++)
{
scanf("%d", &arr[i]);
}
for (j = 0; j < nopgrp;j++)
{
if(arr[j]==1)
{
count++;
}
else if(arr[j]==2)
{
if(arr[j+1]==2)
{
count++;
}
else
{
flag=1;
}
}
else if(arr[j]==3)
{
if((arr[j+1]==3)&&(arr[j+2]==3))
{
count++;
}
else
{
flag=2;
}
}
else if(arr[j]==4)
{
if((arr[j+1]==4)&&(arr[j+2]==4)&&(arr[j+3]==4))
{
count++;
}
else
{
flag=3;
}
}
else if(arr[j]==5)
{
if((arr[j+1]==5)&&(arr[j+2]==5)&&(arr[j+3]==5)&&(arr[j+4]==5))
{
count++;
}
else
{
flag=4;
}
}
else if(arr[j]==6)
{
if((arr[j+1]==6)&&(arr[j+2]==6)&&(arr[j+3]==6)&&(arr[j+4]==6)&&(arr[j+5]==6))
{
count++;
}
else
{
flag=5;
}
}
else if(arr[j]==7)
{
if((arr[j+1]==7)&&(arr[j+2]==7)&&(arr[j+3]==7)&&(arr[j+4]==7)&&(arr[j+5]==7)&&(arr[j+6]==7))
{
count++;
}
else
{
flag=6;
}
}
else if(arr[j]==8)
{
if((arr[j+1]==8)&&(arr[j+2]==8)&&(arr[j+3]==8)&&(arr[j+4]==8)&&(arr[j+5]==8)&&(arr[j+6]==8)&&(arr[j+7]==8))
{
count++;
}
else
{
flag=7;
}
}
else if(arr[j]==9)
{
if((arr[j+1]==9)&&(arr[j+2]==9)&&(arr[j+3]==9)&&(arr[j+4]==9)&&(arr[j+5]==9)&&(arr[j+6]==9)&&(arr[j+7]==9)&&(arr[j+8]==9))
{
count++;
}
else
{
flag=8;
}
}
else if(arr[j]==0)
{
flag=9;
}
}
if(flag!=0)
{
printf("Invalid Data");
flag=0;
}
else
{
printf("%d\n",count);
count=0;
}
t--;
}
return 0;
}
if((arr[j+1]==9)&&(arr[j+2]==9)&&(arr[j+3]==9) ...)
You can simplify the above code with another for loop. Evidently you just want to see how many different numbers there are in the array.
Note that one of the main reasons to use C, or to learn C, is for efficiency. Therefore int arr[1000] is somewhat out of place because it allocates 4000 bytes. You may want to streamline that with malloc/free.
You should use printf to tell the user what to input.
I took some guesses on what you are trying achieve.
int tcaseno, nopgrp, error;
int count, i;
int *arr;
printf("no_test_cases: ");
scanf("%d", &tcaseno);
while(tcaseno > 0)
{
error = 0;
count = 1;
printf("no_people_in_group: ");
scanf("%d", &nopgrp);
if(nopgrp > 0 && nopgrp < 1000)
{
arr = malloc(nopgrp * sizeof(int));
printf("Enter %d numbers: ", nopgrp);
for(i = 0; i < nopgrp; i++)
scanf("%d", &arr[i]);
for(i = 1; i < nopgrp; i++)
{
if(arr[i - 1] > arr[i])
error = 1;
else if(arr[i - 1] != arr[i])
count++;
}
free(arr);
}
else
error = 1;
if(error)
printf("Invalid Data\n");
else
printf("Result: %d\n", count);
tcaseno--;
}
I'm a newbie in C. I'm on the verge of finishing a program. Can anybody teach me how to make a countdown timer while being able to input something? I'm currently using sleep(), and as I've heard, it's bad for threading, and freezes input. Is that right?
Here's the function:
void nowPlaying(SONG * h, SONG * t, int * randPrev, int shuffleCon)
{
SONG * ptr;
ptr = h->next;
int random, randCount, mincount = 0, choice = 4, tot = 0, tot2 = 0;
if(h->next == t) {
printf("No songs to be played. Add some!\n");
}
else if(h->next != t) {
while(ptr->next != t) {
tot2 = tot = ((ptr->cdown.minutes*60) + ptr->cdown.secs);
do {
printf("------------------------YouTunes------------------------\n");
printf("========================================================\n");
printf("TITLE : %s \n", ptr->title);
printf("ARTIST: %s \n", ptr->artist);
printf("ALBUM : %s \n", ptr->album);
switch(ptr->genre) {
case 1:
printf("GENRE : POP \n");
break;
case 2:
printf("GENRE : OPM \n");
break;
case 3:
printf("GENRE : ROCK \n");
break;
case 4:
printf("GENRE : R&B \n");
break;
case 5:
printf("GENRE : ACOUSTIC \n");
break;
case 6:
printf("GENRE : CLASSICAL \n");
break;
}
while(tot2 >= 60) {
tot2 = tot2 - 60;
mincount++;
//if(time_left % 60 == 0) mincount++;
}
printf("TIME: ");
if(mincount < 10)
printf("0%d", mincount);
else
printf("%d", mincount);
printf(":");
if(tot2 < 10)
printf("0%d", tot2);
else if(tot2 == 60)
printf("00");
else
printf("%d", tot2);
printf("\n========================================================\n");
printf("[1] Prev [0]Exit [2] Next\n");
printf("Choice: ");
//scanf("%d", &choice);
//timeout(500);
tot--;
tot2 = tot;
mincount = 0;
sleep(1);
system("clear");
if(shuffleCon == 0) {
if(choice == 1) {
if(ptr->prev == h) {
//do nothing
}
else if(ptr->prev != h) {
ptr = ptr->prev;
}
}
else if(choice == 2) {
if(ptr->next == t) {
//do nothing
}
else if(ptr->next != t) {
ptr = ptr->next;
}
}
}
else if(shuffleCon == 1) {
if(choice == 1) {
random = shuffle(h, t, randPrev);
randCount = 0;
ptr = h->next;
while(randCount != random) {
ptr = ptr->next;
randCount++;
}
}
else if(choice == 2) {
random = shuffle(h, t, randPrev);
randCount = 0;
ptr = h->next;
while(randCount != random) {
ptr = ptr->next;
randCount++;
}
if(ptr == t) {
ptr = ptr->prev;
ptr = ptr->prev;
}
}
}
} while(tot != -1);
if(shuffleCon == 0)
ptr = ptr->next;
else if(shuffleCon == 1) {
random = shuffle(h, t, randPrev);
randCount = 0;
ptr = h->next;
while(randCount != random) {
ptr = ptr->next;
randCount++;
}
}
}
}
}
Broadly speaking, one of these:
Use SIGALRM (see the alarm man page), and rely on the signal to interrupt the system call expecting user input.
(Better, and certainly a more valuable programming exercise), write an event loop with select or poll and set the timeout to be the time remaining until the timeout.
For the sort of application you are talking about, (2) would be a better choice.