For exact question see this link
Here I defined three function, called them selves one within another.
Function call is not being done
#include<stdio.h>
int primegen(int x1,int x2);
int isprime(int j);
int main(){
int x,n1,n2,i;
printf("Enter the number of test cases:");
scanf("%d",&x);
for(i=0;i<x;i++){
printf("enter the starting point and ending point:");
scanf("%d %d",&n1,&n2);
primegen(n1,n2);
}
return 0;
}
int primegen(int x1,int x2){
int k;
if(x2>x1){
for(k=x1;k<x2;k++){
if(isprime(k))
{
printf("%d",k);
}
}
return 0;
}
}
int isprime(int j){
int i,c=0;
for (i=1;i<=j;i++)
{
if(j%i==0){
c++;
}
if(c!=2){
return 0;
}
else{
return 1;
}
}
}
Output
There is no output for this code.
Take following outside loop:
if(c!=2){
return 0;
}
else{
return 1;
}
The problem is in your loop in isprime().
In this you are using the value of c when it is still 0. So, c!=2 would result in true and 0 will be returned and you would not get any answer.
Remove this particular statement from the for loop as you need to calculate total no. of divisors.
for (i=1;i<=j;i++)
{
if(j%i==0)
c++;
}
if(c!=2)
return 0;
else
return 1;
Or you can do like this:
int isprime(int j){
int i,k;
k=sqrt(j); //include math.h for this
for(i=2;i<=k;i++)
{
if(j%i==0)
return 1;
}
return 0;
}
You only need to find any divisor up to the square root of the number.
It's better to return 0 if it is found to be divisible instead of using counter and incrementing it.
int isprime(int j)
{
int i;
for(i=2;i<j;i++)
if((j%i)==0)
return 0;
return 1;
}
#include <stdio.h>
#include <math.h>
int main()
{
int test;
scanf("%d",&test);
while(test--)
{
unsigned int low,high,i=0,j=2,k,x=0,y=0,z;
unsigned long int a[200000],b[200000];
scanf("%d",&low);
scanf("%d",&high);
for(i=low;i<=high;i++)
a[x++]=i;
for(i=2;i<=32000;i++)
b[y++]=i;
i=0;
while(b[i]*b[i]<=high)
{
if(b[i]!=0)
{
k=i;
for(;k<y;k+=j)
{
if(k!=i)
{
b[k]=0;
}
}
}
i+=1;j+=1;
}
for(i=0;i<y;i++)
{
if(b[i]!=0 && (b[i]>=low && b[i]<=sqrt(high)))
printf("%d\n",b[i]);
}
int c=0;
for(i=0;i<y;i++)
{
if(b[i]!=0 && (b[i]>=1 && b[i]<=sqrt(high)))
b[c++]=b[i];
}
int m=a[0];
for(i=0;i<c;i++)
{
z=(m/b[i])*b[i];k=z-m;
if(k!=0)
k += b[i];
for(;k<x;)
{
if(a[k]!=0)
{
a[k]=0;
}
k+=b[i];
}
}
for(i=0;i<x;i++)
{
if(a[i]!=0 && (a[i]>=2 && a[i]<=(high)))
printf("%d\n",a[i]);
}
printf("\n");
}
return 0;
}
Related
#include <stdio.h>
int bsearch(int ar[],int n,int key)
{
int s=0;
int e=n-1;
while(s<=e){
int mid=(e+s)/2;
if(mid==key){
return mid;
}
else if(key<mid){
e=mid-1;
}
else if(key>mid){
s=mid+1;
}
}
return -1;
}
I made the function for the binary search
int main()
{
int n,key;
int ar[n];
scanf("%d",&n);
for(int i=0;i<n;i++){
printf("ar[%d]= ",i);
scanf("%d",&ar[i]);
}
printf("Enter key>> \n");
scanf("%d",&key);
printf("%d is the index",bsearch(ar,n,key));
return 0;
}
Then I inputted an sorted array but with repetitions. Shown in the following image.
The output is coming as 3 is the index.
But it should as come as 6 is the index.
mid is an index of element, not a value. So, I have corrected your function:
#include <stdio.h>
int bsearch(int ar[], int n, int key)
{
int s=0;
int e=n-1;
while(s <= e){
int mid = (e + s) / 2;
if(key == ar[mid]) {
return mid;
}
else if(key < ar[mid]) {
e = mid-1;
}
else if(key > ar[mid]) {
s = mid+1;
}
}
return -1;
}
I've written a very simple program which calculate the factorial of a number, the problem is that from 30 to 60 approximately, it returns a negative number and from 70 it returns 0.
I don't what I've done wrong. Could this problem depend on the computing power of my computer?
Here's the code:
#include <stdio.h>
int main(){
int x, i;
long long int f = 1;
printf("Insert a number:");
scanf("%d", &x);
if (x == 0){
printf("0! = 1");
}
else {
for (i = 1; i <= x; i++){
f *= i;
}
printf("%d! รจ = %lli", x, f);
}
return 0;
}
Here is my code:
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
void Carry(int bit[],int pos)
{
int i,carray=0;
for(i=0;i<=pos;i++)
{
bit[i]+=carray;
if(bit[i]<=9)
{
carray=0;
}
else if(bit[i]>9&&i<pos)
{
carray=bit[i]/10;
bit[i]%=10;
}
else if(bit[i]>9&&i>=pos)
{
while(bit[i]>9)
{
carray=bit[i]/10;
bit[i]%=10;
i++;
bit[i]=carray;
}
}
}
}
int main()
{
int num,pos,digit,i,j,m,n;
double sum=0;
int *fact;
printf("input want to calculute factorial num:");
scanf("%d",&num);
for(i=1;i<=num;i++)
{
sum+=log10(i);
}
digit=(int)sum+1;
if(!(fact=(int *)malloc((digit+1)*sizeof(int))))
{
printf("malloc failed\n");
return 0;
}
for(i=0;i<=digit;i++)
{
fact[i]=0;
}
fact[0]=1;
for(i=2;i<=num;i++)
{
for(j=digit;j>=0;j--)
{
if(fact[j]!=0)
{
pos=j;
break;
}
}
for(j=0;j<=pos;j++)
{
fact[j]*=i;
}
Carry(fact,pos);
}
for(j=digit;j>=0;j--)
{
if(fact[j]!=0)
{
pos=j;
break;
}
}
m=0;
n=0;
for(i=pos;i>=0;i--)
{
printf("%d",fact[i]);
m++;
if(m%4==0)
{
printf(" ");
}
if(m==40)
{
printf("\n");
m=0;
n++;
if(n==10)
{
printf("\n");
n=0;
}
}
}
printf("\n\n");
return 0;
}
Its a easy sorting problem.The problem link is https://www.hackerearth.com/practice/algorithms/sorting/quick-sort/practice-problems/algorithm/kings-race-8/
When i use global array variable the program get accepted.But when i use local array variable memory limit exceeded in case 6 and runtime error in cases 8,9,10.Why this is happened?
My code with local array variable:
#include<stdio.h>
void Quick_Sort(int a[][2],int Start,int End)
{
if(Start<End)
{
int Piv_pos=Partition(a,Start,End);
Quick_Sort(a,Start,Piv_pos-1);
Quick_Sort(a,Piv_pos+1,End);
}
}
int Partition(int a[][2],int Start,int End)
{
int i=Start+1,j,temp;
int Pivot=a[Start][0];
for(j=Start+1;j<=End;j++)
{
if(a[j][0]<Pivot)
{
temp=a[j][0];
a[j][0]=a[i][0];
a[i][0]=temp;
temp=a[j][1];
a[j][1]=a[i][1];
a[i][1]=temp;
i++;
}
}
temp=a[Start][0];
a[Start][0]=a[i-1][0];
a[i-1][0]=temp;
temp=a[Start][1];
a[Start][1]=a[i-1][1];
a[i-1][1]=temp;
return i-1;
}
int min(int a,int b)
{
if(a<b)
return a;
else
return b;
}
int main()
{
int T,i,j,N,K,prince_ind;
scanf("%d",&T);
while(T--)
{
scanf("%d%d",&N,&K);
int a[N][2],h[K];
for(i=0;i<N;i++)
{
scanf("%d",&a[i][0]);
a[i][1]=i;
}
Quick_Sort(a,0,N-1);
/* for(i=0;i<N;i++)
{
printf("%d ",a[i][0]);
}*/
for(i=0;i<K;i++)
{
scanf("%d",&h[i]);
}
for(i=0,j=0;i<K&&j<N;i++)
{
prince_ind=a[j][1];
while(a[j][0]<h[i]&&j<N)
{
prince_ind=min(prince_ind,a[j][1]);
j++;
}
}
while(j<N)
{
prince_ind=min(prince_ind,a[j][1]);
j++;
}
printf("%d\n",prince_ind);
}
return 0;
}
My code with global array variable:
#include<stdio.h>
int a[1000000][2],h[1000000];
void Quick_Sort(int Start,int End)
{
if(Start<End)
{
int Piv_pos=Partition(Start,End);
Quick_Sort(Start,Piv_pos-1);
Quick_Sort(Piv_pos+1,End);
}
}
int Partition(int Start,int End)
{
int i=Start+1,j,temp;
int Pivot=a[Start][0];
for(j=Start+1;j<=End;j++)
{
if(a[j][0]<Pivot)
{
temp=a[j][0];
a[j][0]=a[i][0];
a[i][0]=temp;
temp=a[j][1];
a[j][1]=a[i][1];
a[i][1]=temp;
i++;
}
}
temp=a[Start][0];
a[Start][0]=a[i-1][0];
a[i-1][0]=temp;
temp=a[Start][1];
a[Start][1]=a[i-1][1];
a[i-1][1]=temp;
return i-1;
}
int min(int a,int b)
{
if(a<b)
return a;
else
return b;
}
int main()
{
int T,i,j,N,K,prince_ind;
scanf("%d",&T);
while(T--)
{
scanf("%d%d",&N,&K);
//int a[N][2],h[K];
for(i=0;i<N;i++)
{
scanf("%d",&a[i][0]);
a[i][1]=i;
}
Quick_Sort(0,N-1);
/* for(i=0;i<N;i++)
{
printf("%d ",a[i][0]);
}*/
for(i=0;i<K;i++)
{
scanf("%d",&h[i]);
}
for(i=0,j=0;i<K&&j<N;i++)
{
prince_ind=a[j][1];
while(a[j][0]<h[i]&&j<N)
{
prince_ind=min(prince_ind,a[j][1]);
j++;
}
}
while(j<N)
{
prince_ind=min(prince_ind,a[j][1]);
j++;
}
printf("%d\n",prince_ind);
}
return 0;
}
I'm trying to write sliding puzzle where I'm using 3x3 matrix as board. In main function user inputs the number of tile which swaps positions with 0. Everything works except when I enter number that is located in a position above zero it does not swap positions with it. How do I correct that?
Here's the code:
#include <stdio.h>
#include <stdlib.h>
#define empty_space 0
int m,n,i,j,z,y;
void print_matrix(int matrix[3][3])
{
for ( m=0; m<3; m++){
for (n=0; n<3; n++)
{
printf("%d\t",matrix[m][n]);
} printf("\n");
}
printf("\n");
}
void swap(int *i, int *j) {
int t = *i;
*i = *j;
*j = t;
}
void slide(int a[3][3] , int t)
{
for ( i=0; i<3; i++){
for ( j=0; j<3; j++)
{
if (a[i][j]==t)
{
if (a[i+1][j]==empty_space && i+1<=2)
{
swap(&a[i+1][j],&a[i][j]);break;
}
if (a[i-1][j]==empty_space && i-1>=0)
{
swap(&a[i][j],&a[i-1][j]);break;
}
if (a[i][j+1]==empty_space && j+1<=2)
{
swap(&a[i][j],&a[i][j+1]);break;
}
if (a[i][j-1]==empty_space && j-1>=0)
{
swap(&a[i][j],&a[i][j-1]);break;
}
}
}
}
}
int goal_test (int a[3][3],int b[3][3])
{
int flag=0;
for ( z=0; z<3; z++){
for ( y=0; y<3; y++){
if(a[z][y]==b[z][y])
flag++;
}
}
if (flag==9)
return 1;
else return 0;
}
int main()
{
static int mat[3][3]={{1,2,3},{6,0,4},{7,5,8}};
int goal[3][3]={{1,0,3},{6,5,4},{7,8,2}};
print_matrix(mat);
int x;
while(goal_test(mat,goal)==0)
{
printf("enter tile to slide:\t");
scanf("%d",&x);
slide(mat, x);
print_matrix(mat);
}
return 0;
}
Here's what happens:
Any number can swap its position as long as it's not located above zero
i am pursuing the course on programming and data structures in nptel's MOOC.
A programming assignment in the course requires us to calculate sum of selected coefficients.
Now the program i wrote calculated the answer , but i am experiencing a runtime error.
Now i had this inclination of using gets() instead of scanf() so as to speed up my input.
how do i do that?
the code is as follows:
#include<stdio.h>
int combi(int ,int);
long fact(int);
int main()
{
int r,i,v[20],p[20],t,l=1,b=0,sum=0,a=0,flag=0;
char ch='a';
scanf("%d",&r);
scanf("%d",&t);
for(i=0;i<t;i++)
{
scanf("%d",&v[0]);
if(getchar()==' ')
{
if(r<v[0])
{
while(ch!='\n')
{
scanf("%d",&v[l]);
l++;
if(getchar()=='\n')
{
p[a]=-1;
a++;
l=1;
break;
}
}
}
else
{
while(ch!='\n')
{
scanf("%d",&v[l]);
if(v[l]>v[0])
{
flag=1;
}
l++;
if(getchar()=='\n')
{
if(flag>0)
{
p[a]=-1;
a++;
l=1;
sum=0;
flag=0;
break;
}
else
{
for(b=1;b<l;b++)
{
sum=sum+combi(v[0],v[b]);
}
p[a]=sum;
a++;
sum=0;
l=1;
break;
}
}
}
}
}
}
for(i=0;i<t;i++)
{
printf("%d\t ",p[i]);
}
printf("\n");
}
int combi(int x,int y)
{
int a=fact(x)/(fact(x-y)*fact(y));
return a;
}
long fact(int z)
{
int i=1;
long f=1;
while(i<=z)
{
f=f*i;
i++;
}
return f;
}