//wap to find sum of series 1^2,3^2,5^2,7^2.......nth term.
#include<stdio.h>
#include<math.h>
int main(){
    int i,n,sum=0,x,y;
    printf("enter a number upto which u want sum : \n");
    scanf("%d",&n); //5
    for(i=1;i<=n;i=i+2){
        x=pow(i,2);
        sum=sum+x;
    }
    printf("sum is %d",sum);//35
}
//wap to enter marks of 5 diff subjects and find result. find result as passed if he/she gets 40 out of 100 in each subject. Also calculate the percentage and division as:
// If percent is >= 80, => Distinction
// If percent is >= 70, first division
//If percent is >=55, second division
//If percent is >=40, passed , otherwise failed.
#include<stdio.h>
#include<math.h>
int main (){
    int mark,percent,a,b,c,d,e;
    printf("enter marks of 5 different subjects");
    scanf("%d%d%d%d%d",&a,&b,&c,&d,&e);
    mark=a+b+c+d+e;
    if(a>=40&&b>=40&&c>=40&&d>=40&&e>=40){
        printf("You've passed the exam");
    }
    else{
        printf("You've failed, keep working hard");
    }
    percent=mark/5;
    printf("\nYour percentage is %d",percent);
    if(percent>=80){
        printf("\nDistinction");
    }
    else if(percent>=70){
        printf("\nFirst Division");
    }
    else if(percent>=55){
        printf("\nSecond Division");
    }
    else if(percent>=40){
        printf("\nJust Passed");
    }
    else{
        printf("\n So, you've got no rank");
    }
}
//6. NTC charges the following rate for local calls from a customer.
//CALLS        //CHARGES
//<=175         Rs 200
// >175         Rs 1 per extra call
//TSC =10% of Total Charge
//VAT=13%(Total charge+TSC)
//WAP to display all the info including the amount paid by the customer, if the total number of calls is given.
#include<stdio.h>
#include<math.h>
int main(){
    int calls,charges,vat,tsc,total;
    printf("enter total number of calls");
    scanf("%d",&calls);
    if(calls<=175){
        charges=200;
    }
    else if(calls>=175){
        charges=200+(calls-175);
    }
        tsc=0.1*charges;
        vat=0.13*(charges+tsc);
    printf("Total charge is %d, tsc is %d and vat is %d",charges,tsc,vat);
    return 0;
}
//WAP to input all side of triangle and check whether triangle is valid or not.
#include<stdio.h>
#include<math.h>
int main(){
int a,b,c;
printf("enter all 3 sides of a triangle");
scanf("%d%d%d",&a,&b,&c);
if(a>0&&b>0&&c>0&&a+b>c&&b+c>a&&a+c>b){
    printf("triangle is valid");
}
else{
    printf("Invalid triangle");
}
return 0;
}
//WAP to find greatest number among three given by the user using ternary operator.
#include<stdio.h>
#include<math.h>
int main(){
    int a,b,c;
    printf("enter 3 numbers");
    scanf("%d%d%d",&a,&b,&c);
    (a>b&&a>c)?printf("%d is greater",a):(b>c)?printf("%d is greater",b):printf("%d is greater",c);
    return 0;
}
//WAP to input angle of a triangle and check whether triangle is valid or not.
#include<stdio.h>
#include<math.h>
int main(){
    int a,b,c;
    printf("enter 3 angles of a triangle");
    scanf("%d%d%d",&a,&b,&c);
    if(a>0&&b>0&&c>0&&a+b+c==180){
        printf("Triangle is valid");
    }
    else{
        printf("Invalid Triangle");
    }
    return 0;
}
//WAP to display all those armstrong numbers from 100 to 500 and count the displayed numbers.
#include<stdio.h>
#include<math.h>
    int main(){
        int i,a,b,sum;
        for(i=100;i<500;i++){
            int num=i;
                sum=0;
            while(num>0){
                a=num%10;
                b=pow(a,3);
                sum=sum+b;
                num=num/10;
            }
            if(sum==i){
                printf("%d \n",i);
            }
        }
    }
//WAP to swap first and last digit of a number.
#include<stdio.h>
#include<math.h>
int main(){
    int n,a,swap=0;
    printf("enter any number");//345
    scanf("%d",&n);
    while(n>0){
        a=n%10; //345%10=5
        n=n/10;//345/10=34
        swap=a;
    printf("%d",swap);
    }
}
//Write a menu driven program to have the following menu:
//a) factorial
// b) Area and perimeter of rectangle.
// c) Exit
// The program must repeat until user wants.
#include<stdio.h>
#include<math.h>
int main(){
    int press;
   do{
     printf("Press 1 to find factorail.\n Press 2 tp find area and perimeter of rectange.\n Press 3 to exit the program.");
    scanf("%d",&press);
    switch(press){
        case 1:{
            int f,fact=1;
            printf("enter num to find factorial");
            scanf("%d",&f);
            for(int i=f;i>=1;i--){
                    fact=i*fact;
            }
            printf("%d is factorial \n",fact);
            break;
        }
        case 2:{
            int l,b;
            printf("enter length and breadth of rectangle");
            scanf("%d%d",&l,&b);
            int area=l*b;
            int peri=2*(l+b);
            printf("area is %d and perimeter is %d \n",area,peri);
            break;
        }
        case 3:{
            break;
        }
        default :{
            printf("Invalid number, try again. \n");
        }
    }
   }
        while(press!=3);
        return 0;
}