C string capitalize problem. I encounter bus error - pointers

I am making capitalized function. But when execute this code, the bus error occur. Is there anyone can debug this? I really need your help!! please help me . I am computer programming novice without c knowledge.
#include <stdio.h>
void up(char *c)
{
if((*c < ‘z’) && (*c > ‘a’))
{
*c -= 32;
}
}
char *ft_strcapitalize(char *str)
{
int i;
i=0;
while (str[i])
{
up(&str[i]);
i++;
}
return str;
}
int main()
{
char *str = “salut, comment tu vas ? 42mots quarante-deux cinquante”;
ft_strcapitalize(str);
printf(“%s”, str);
}

This solution should work for you.
#include <stdio.h>
void up(char *c)
{
if (!c)
return;
if((*c <= 'z') && (*c >= 'a'))
*c -= 32;
}
char *ft_strcapitalize(char *str)
{
int i;
for (i = 0; str[i]; i++)
up(&str[i]);
return str;
}
int main()
{
char str[] = "salut, comment tu vas ? 42mots quarante-deux cinquante";
ft_strcapitalize(str);
printf("%s\n", str);
return 0;
}

Related

confusing pointer error while implementing linked list

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#define MALLOC(p,s) {\
if (!((p) = malloc(s))) { \
fprintf(stderr, "insufficient memory");\
exit(EXIT_FAILURE);\
}\
}
#define IS_EMPTY(first) (!first)
typedef struct listNode* listPointer;
typedef struct listNode {
int data;
listPointer link;
}listNode;
void printList(listPointer first);
int main(void)
{
int x;
int tmpData;
listPointer first = NULL;
listPointer tmpLink = NULL;
FILE* fp = NULL;
if (!(fp = fopen("in.txt", "r"))) {
fprintf(stderr, "cannot open the file");
exit(EXIT_FAILURE);
}
while (!feof(fp)) {
fscanf(fp, "%d", &tmpData);
MALLOC(tmpLink, sizeof(listNode));
if (IS_EMPTY(first)) {
MALLOC(first, sizeof(listNode));
*tmpLink = *first;
}
tmpLink->data = tmpData;
tmpLink = tmpLink->link;
}
printList(first);
}
void printList(listPointer first)
{
for (; first; first = first->link) {
printf("%d ", first->data);
}
printf("\n");
}
We know that we can implement the insert function.
But I'm really curious about why this doesn't work.
What "first" refers to and what "tmpLink" refers to is the same
After implementing the link list while updating tmpLink,
I'm going to use "first" to print later.
I've spent almost a day just thinking about this, and I've tried debugging it, but I don't know why.

I am trying to print Reverse of a Sequence of Numbers using Stack. Stack is implemented using Vector. But I am getting Segmentation Fault

Can you please help me find the error in printing the reverse of sequence using stacks implemented by vector?
I am getting a Segmenattion fault
#include <iostream>
#include<vector>
using namespace std;
class stack{
public :
int top;
vector<int> data;
bool isempty(){return top == -1;}
void push(int x){data[++top] = x;}
void pop(){--top;}
int topper(){return data[top];}
};
int main()
{
stack s;
int n;
s.top = -1;
cout << "enter the number of integers" << endl;
cin >> n;
for(int i =0; i < n; i ++){
s.push(i);
}
while(!s.isempty()){
cout << s.topper();
s.pop();
}
return 0;
}
This problem occurs, because a vector has size = 0 by default.
You can either resize the vector, before you add values into it like so:
#include <iostream>
#include<vector>
using namespace std;
class stack {
public:
int top;
vector<int> data;
bool isempty() { return top == -1; }
void push(int x) { data.resize(++top+1); data[top] = x; }
void pop() { --top; }
int topper() { return data[top]; }
};
int main()
{
stack s;
int n;
s.top = -1;
cout << "enter the number of integers" << endl;
cin >> n;
for (int i = 0; i < n; i++) {
s.push(i);
}
while (!s.isempty()) {
cout << s.topper();
s.pop();
}
return 0;
}
Or you can use the built-in functionality for vectors like that, which I think is the far better solution:
#include <iostream>
#include<vector>
using namespace std;
class stack {
public:
vector<int> data;
bool isempty() { return data.size() == 0; }
void push(int x) { data.push_back(x); }
void pop() { data.pop_back(); }
int topper() { return data.back(); }
};
int main()
{
stack s = stack();
int n;
cout << "enter the number of integers" << endl;
cin >> n;
for (int i = 0; i < n; i++) {
s.push(i);
}
while (!s.isempty()) {
cout << s.topper();
s.pop();
}
return 0;
}

Segmentation fault inside range

#include <iostream>
#include <vector>
#include <algorithm>
#include <queue> // std::priority_queue
using std::vector;
using std::cin;
using std::cout;
struct fj{
int indexI=0;
int freeT=0;
};
struct DereferenceCompareNode : public std::binary_function<fj, fj, bool>
{
bool operator()(const fj lhs, const fj rhs) const
{
return lhs.freeT > rhs.freeT;
}
};
class JobQueue {
private:
int num_workers_;
vector<int> jobs_;
vector<int> assigned_workers_;
vector<long long> start_times_;
void WriteResponse() const {
for (int i = 0; i < jobs_.size(); ++i) {
cout << assigned_workers_[i] << " " << start_times_[i] << "\n";
}
}
void ReadData() {
int m;
cin >> num_workers_ >> m;
jobs_.resize(m);
std::cout<<"Read fault"<<"\n";
for(int i = 0; i < m; i++)
cin >> jobs_[i];
std::cout<<"Read fault ends"<<"\n";
}
void AssignJobs() {
// TODO: replace this code with a faster algorithm.
std::cout<<"Fault point 1"<<"\n";
assigned_workers_.resize(jobs_.size());
start_times_.resize(jobs_.size());
vector<long long> next_free_time(num_workers_, 0);
std::priority_queue<int, vector<int>, std::greater<int> > thread;
std::priority_queue<fj, vector<fj>, DereferenceCompareNode > freeJob;
/*
for (int i = 0; i < jobs_.size(); ++i) {
int duration = jobs_[i];
int next_worker = 0;
for (int j = 0; j < num_workers_; ++j) {
if (next_free_time[j] < next_free_time[next_worker])
next_worker = j;
}
assigned_workers_[i] = next_worker;
start_times_[i] = next_free_time[next_worker];
next_free_time[next_worker] += duration;
}
*/
std::cout<<"dump point 2"<<"\n";
for(int i=0;i<num_workers_;i++){
thread.push(i);
}
std::cout<<"dump point 1"<<"\n";
int counter = 0;
while(jobs_.size()!=0){
std::cout<<"jobs_.size:"<<jobs_.size()<<"\n";
std::cout<<"freeJob.size:"<<freeJob.size()<<"\n";
//check logic
do{
if(freeJob.top().freeT == counter){
std::cout<<"freeJob.top().freeT:"<<freeJob.top().freeT<<"\n";
std::cout<<"counter:"<<counter<<"\n";
thread.push(freeJob.top().indexI);
freeJob.pop();
}else{
break;
}
}
while(freeJob.size()!=0);
std::cout<<"Thread:"<<thread.size()<<"\n";
while(thread.size()!=0){
if(jobs_.size()!=0){
fj currA;
currA.indexI = thread.top();
currA.freeT = jobs_.at(0)+counter;
std::cout<<"currA.indexI:"<<currA.indexI<<"\n";
std::cout<<"currA.freeT:"<<currA.freeT<<"\n";
thread.pop();
jobs_.erase(jobs_.begin());
assigned_workers_.push_back(currA.indexI);
start_times_.push_back(currA.freeT);
}else{
break;
}
}
counter++;
}
}
public:
void Solve() {
ReadData();
AssignJobs();
WriteResponse();
}
};
int main() {
std::ios_base::sync_with_stdio(false);
JobQueue job_queue;
job_queue.Solve();
return 0;
}
I am getting segmentation fault in function ReadData while taking inputs for vector jobs.
I am getting fault even when I am inside bounds of defined size.
Everything was fine when have not written AssignJob function.
Am I doing something wrong with some bounds or taking illegal inputs format or messing with some other stuff?
Am I doing something wrong
Yes, you are: freeJob starts out empty, so this is undefined behavior:
if(freeJob.top().freeT == counter){
In fact, you never push anything into freeJob, you only pop() things from it.

reason for runtime error in my c program &?

#include<stdio.h>
main()
{char *names[4];
int i,a;
printf("ënter the guests names\n");
for(i=0;i<=3;i++)
{
scanf("%s",names[i]);
}
char *yourname;
printf("\nenter your name ");
scanf("%c",yourname);
for(i=0;i<=3;i++)
{a=strcmp(names[i],yourname);
if(a==0)
printf("\nwelcome");
break;
}
if(a!=0)
printf("\naccess denied");
return 0;
}
this is a program to check your entry in a show. first we give permitted names & then it asks your name ,it compares your name with the names in the guest list.
i m getting runtime error, plz tell me the correction.i want to use pointers to string so plz suggest correction in the existing program
when i run this program in devc++ after entering first name it gives program.exe stopped working.
The code will be like this:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
char *names[4];
int i,a;
printf("ënter the guests names\n");
for(i=0;i<=3;i++) {
names[i] = (char*) malloc(100 * sizeof(char));
scanf("%s", names[i]);
}
char yourname[100];
printf("\nenter your name ");
scanf("%s",yourname);
for(i=0;i<=3;i++) {
a = strcmp(names[i], yourname);
if (a == 0) break;
}
if (a==0)
printf("\nwelcome");
else printf("\naccess denied");
for(i=0;i<=3;i++)
free(names[i]);
return 0;
}
Your code have to be formated so we can give you a better answer.
Now, use gets to take your input, verify the guest match with your name inside the for loop, stop the loop when a match is found.
#include<stdio.h>
#include<string.h>
int main()
{
char names[4][20];
int i = 0;
int a = 0;
printf("Enter guests names: \n");
for(i=0; i<3; i++)
{
gets(names[i]);
}
char yourname[20];
printf("\n Enter your name ");
gets(yourname);
printf("\n Verify access right:");
for(i=0; i<3; i++)
{
a=strcmp(names[i], yourname);
if(a==0)
{
printf("\n welcome");
break;
}
else
{
printf("\n access denied");
}
}
return 0;
}
Although this looks like a homework assignment.

casting a struct in c

I need an array of user structs.
struct user {
char *username;
};
struct user users[10]; //Array of user structs
int main(int argc, char **args) {
int initUsersArray();
char *username = "Max";
addToUsersArrry(username);
}
int addToUsersArrry(username) {
int i;
i = 0;
struct user tmp;
for(i;i<10;i++) {
if(users[i] != NULL)
if(strcmp(*users[i].username,username)==0)
return -1;
}
i = 0;
for(i;i<10;i++) {
if(users[i] = NULL) {
users[i]=tmp;
users[i].username=username;
return 1;
}
}
}
int initUsersArray() {
int i;
i=0;
struct user tmp;
for(i;i<10;i++) {
users[i] = (struct user*) calloc(1,sizeof(tmp));
}
}
My first question is, if it is the right way to init the users array with NULL like i did.
The second problem is, that
*users[i].username
and other parts of code where want to get/set the user at a specific position, dont work.
Regards
Here, I fixed it for you. And don't forget to diff and learn something. Don't just c/p it.
#include <stdio.h>
#include <stdlib.h>
typedef struct user {
char *username;
} user;
user *users; //Array of user structs
int addToUsersArray(char *username) {
int i = 0;
for(; i<10; i++) {
if(users[i].username=='\0') {
users[i].username = username;
return 1;
} else if(strcmp(users[i].username, username) == 0)
return -1;
}
return -1;
}
void initUsersArray() {
users = (user*) calloc(10, sizeof(user)); //10 of them
}
int main(int argc, char** argv) {
initUsersArray();
char *username = "Max";
addToUsersArray(username);
username = "Ma1x";
addToUsersArray(username);
printf("%s\n",users[0].username);
printf("%s\n",users[1].username);
return 1;
}

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