series(1+3+5+7+9+...........+n)

#include<stdio.h>
///odd number series:
int main ()
{
    int i,num,sum=0;
    printf("Please enter any number:");
    scanf("%d",&num);

    for(i=1;i<=num;i=i+2)
    {
      printf("%d ",i);
      sum=sum+i;
    }

    printf("\nThe sum of the odd number series is:%d",sum);

    return 0;
}

series(2+4+6+8+............+n)

#include<stdio.h>
///Even number series:
int main ()
{
    int i,num,sum=0;
    printf("Please enter any number:");
    scanf("%d",&num);

    for(i=2;i<=num;i=i+2)
    {
      printf("%d ",i);
      sum=sum+i;
    }

    printf("\nThe sum of the even number series is:%d",sum);

    return 0;
}

series(1/1 + 1/2 + 1/3 + 1/4 + . . . + 1/n----A.P)

#include<stdio.h>
///1/1 + 1/2 + 1/3 + 1/4 + . . . + 1/n
int main()
{

    float num,i,sum=0;

    printf("Please enter any number:\n");
    scanf("%f", &num);

    for (i=1;i<=num;i++)
    {
        sum=sum +(1/i);
        if (i==1)
            printf("\nThe series is: 1+");
        else if (i==num)
            printf("(1/%.0f)\n",i);
        else
            printf("(1/%.0f)+",i);
    }
    printf("\nThe sum of the series is:%.2f\n", sum);
    return 0;
}

series(1^3 + 2^3 + 3^3+ .....+n^3)

///1^3 + 2^3 + 3^3+ .....+n^3
int main(){

    int n,i;
    int sum=0;

    printf("Enter any end number of this series: ");
    scanf("%d",&n);

    sum = (((n*(n + 1) ) / 2))*(((n*(n + 1) ) / 2));

    printf("\nSum of the series:");

    for(i =1;i<=n;i++){
         if (i!= n)
             printf("%d^3+",i);
         else
             printf("%d^3=%d\n ",i,sum);
    }

    return 0;
}

series(1^2 + 2^2 + …. + n^2)

#include<stdio.h>
///1^2 + 2^2 + …. + n^2
int main(){

    int n,i;
    int sum=0;

    printf("Enter any end number of this series: ");
    scanf("%d",&n);

    sum = (n * (n + 1) * (2 * n + 1 )) / 6;

    printf("Sum of the series : ");

    for(i =1;i<=n;i++){
         if (i != n)
             printf("%d^2 + ",i);
         else
             printf("%d^2 = %d ",i,sum);
    }

    return 0;
}

series(1 + 2 + 3 + … + n)

#include<stdio.h>
///1 + 2 + 3 + … + n
int main(){

    int n,i;
    int sum=0;

    printf("Enter any end number of this series: ");
    scanf("%d",&n);

    sum = (n * (n + 1)) / 2;

    printf("Sum of the series: ");

    for(i =1;i <= n;i++){
         if (i!=n)
             printf("%d + ",i);
         else
             printf("%d=%d ",i,sum);
         }

    return 0;
}

Array(3)

#include <stdio.h>
///search a number using an arary using linear search.

int main()
{
int ara[100],i,key,n,loc,ck;
scanf("%d",&n);
for(i=0;i<n;i++)
    scanf("%d",&ara[i]);
    scanf("%d",&key);
    ck=0;
    for(i=0;i<n;i++){
      if (ara[i]==key){
        ck=1;
        loc=i+1;
        break;
      }
    }
    if (ck==1)
        printf("%d",loc);
    else
        printf("No");
        return 0;
}

Array(2)

#include <stdio.h>
///array traversing/array searching

int main()
{
int ara[5]={1,44,67,56,46},i;
///for(i=0;i<5;i++){
 ///   printf("%d ",ara[i]);
///}
///for(i=4;i>=0;i--){
   printf("%d ",ara[3]);
///}
return 0;
}

Array(1)

#include <stdio.h>
///array_declare

int main()
{
int ara[5]={1,2,4,6,99},i;
ara[0]=5;
ara[3]=66;

for(i=0;i<5;i++){
    printf("%d\n",ara[i]);
}
return 0;
}

string(11)

#include <stdio.h>
///string function:
///***strspn ,strcspn****

///int main()
///{
///char str1[100]="koushik";
///char str2[100]="kbcdef";
///int len;
///len=strspn(str1,str2);
///printf("%d\n",len);
///return 0;
///}



int main()
{
char str1[100]="koushik";
char str2[100]="abcdhf";
int len;
len=strcspn(str1,str2);
printf("%d\n",len);
return 0;
}

string(10)

#include <stdio.h>
#include <string.h>
///string (function)

///int main()
///{
///char str[100]="koushik";
///strlen(str);
///printf("%d\n",strlen(str));
///return 0;
///}


///int main()
///{
///char str1[100]="koushik";
///char str2[100]="Ahamed";
///strcpy(str1,str2);
///printf("%s\n",str1);
///return 0;
///}


///int main()
///{
///char str1[100]="koushik";
///char str2[100]="Ahamed";
///strncpy(str1,str2,3);
///str1[3]='\0';
///printf("%s\n",str1);
///return 0;
///}

///int main()
///{
///char str1[100]="koushik";
///char str2[100]="Ahamed";
///strcat(str1," ");
///strcat(str1,str2);
///printf("%s\n",str1);
///return 0;
///}

///int main()
///{
///char str1[100]="koushik";
///char str2[100]="Ahamedkushal";
///strncat(str1,str2,6);
///printf("%s\n",str1);
///return 0;
///}


///int main()
///{
///char str1[100]="BCD";
///char str2[100]="AYZ";
///strcmp(str1,str2);
///printf("%d",strcmp(str1,str2));
///return 0;
///}


///int main()
///{
///char str1[100]="BCD";
///char str2[100]="XYZ";
///strcmp(str1,str2);
///printf("%d",strcmp(str1,str2));
///return 0;
///}


///int main()
///{
///char str1[100]="BCD";
///char str2[100]="BCD";
///strcmp(str1,str2);
///printf("%d",strcmp(str1,str2));
///return 0;
///}


///int main()
///{
///char str1[100]="BCD";
///char str2[100]="BCD";
///if(strcmp(str1,str2)==0);
///printf("They are same\n");
///return 0;
///}


///int main()
///{
///char str1[100]="BCD";
///char str2[100]="BCD";
///if(!strcmp(str1,str2));
///printf("They are same\n");
///return 0;
///}


///int main()
///{
///char str1[100]="BBD";
///char str2[100]="BDB";
///strncmp(str1,str2,2);
///printf("%d",strncmp(str1,str2,2));
///return 0;
///}


///int main()
///{
///char str1[100]="BBD";
///char str2[100]="BBB";
///if(!strncmp(str1,str2,2));
///printf("They are same\n");
///return 0;
///}


int main()
{
char str1[100]="BBB";
char str2[100]="BBB";
printf("%d",strcoll(str1,str2));
return 0;
}

///***strcmp and strcoll closely same ***///

string(9)

#include <stdio.h>
#include <string.h>

int main()
{
char n1[100],n2[100];
while(scanf("%s%s",n1,n2) !=EOF){
  ///  if(strchr(n1)>strchr(n2))
    ///    printf("a > b \n");
   ///else if(strchr(n1)<strchr(n2))
     ///   printf("a < b \n");
   if(strlen(n1)>strlen(n2))
        printf("a > b \n");
   else if(strlen(n1)<strlen(n2))
        printf("a < b\n");
   else if(strcmp(n1,n2)==0)
   printf("a = b\n");
   else if(strcmp(n1,n2)>0)
   printf("a > b\n");
   else
       printf("a < b\n");

}
return 0;
}

string(8)

#include <stdio.h>
///copy a string to another string

int main()
{
    char ch[15],ch1[15];
    int i;
    scanf("%s",ch);
    for(i=0;ch[i]!='\0';i++)

    ch1[i]=ch[i];
    ch1[i]=ch[i];
    printf("%s",ch1);

    return 0;
}

string(7)

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char ch[15],ch1[15];
    int i,n;
    scanf("%s%s",ch,ch1);
    for(i=0;ch[i]!='\0';i++);
        ch[i]=' ';
       i++;

    for(n=0;ch1[n]!='\0';n++)
        ch[i+n]=ch1[n];
    printf("%s",ch);

    return 0;
}

string(6)

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char ch[10][100],i,n;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        scanf("%s",ch[i]);
    }
    for(i=n-1;i>=0;i--){
        printf("%s\n",ch[i]);
    }
    return 0;
}

string(5)

#include <stdio.h>
#include <stdlib.h>

int main()
{
char ch[100];
gets(ch);
int a,b;
printf("%*.*s",10,5,ch);
return 0;
}

string(4)

#include <stdio.h>
#include <stdlib.h>

int main()
{
char ch[100];
while(gets(ch)){
    if(ch[0]=='\0')
        return 0;
    printf("%s\n",ch);
}
return 0;
}

string(3)

#include <stdio.h>
#include <stdlib.h>

///int main()
///{
    ///char ch[100];
   /// scanf("%[^\n]",ch);////***same output
  ///  printf("%s",ch);
  ///  return 0;
//}
int main()
{
    char ch[100];
    gets(ch);///***same output
    printf("%s",ch);
    return 0;
}

string(2)

#include <stdio.h>
#include <stdlib.h>

int main()
{
char str[100];
gets(str);
printf("%s\n",str);
gets(str);
printf("%s\n",str);
gets(str);
printf("%s\n",str);
return 0;
}

string(1)

#include <stdio.h>
///character string & array:

int main()
{
char ch[10];

ch[0]='K';
ch[1]='o';
ch[2]='u';
ch[3]='s';
ch[4]='h';
ch[5]='i';
ch[6]='k';
ch[7]='\0';///string terminating character:
ch[8]='t';
ch[9]='m';

printf("%s",ch);

return 0;
}