1.




#include <stdio.h>
#include <math.h>

struct point1 {
    int x1;
    int y1;
};

struct point2 {
    int x2;
    int y2;
};


main(){

    struct point1 P;
    struct point2 Q;

    int a,b,c;

    printf("Enter the value of x1: ");
    scanf("%d",&P.x1);
    printf("Enter the value of y1: ");
    scanf("%d",&P.y1);
    printf("Enter the value of x2: ");
    scanf("%d",&Q.x2);
    printf("Enter the value of y2: ");
    scanf("%d",&Q.y2);

    a = P.x1-Q.x2;
    if(a<0)
        a*(-1);

    b = P.y1-Q.y2;
    if(b<0)
        b*(-1);

    c = a+b;

    printf("M.D. = %d",c);






}





2.


struct student{
    int id;
    float sub1;
    float sub2;
    float sub3;
};


main(){

    struct student info;
    float max,total;


    printf("Enter student ID: ");
    scanf("%f",&info.id);

    printf("Enter 1st subject mark: ");
    scanf("%f",&info.sub1);

    max = info.sub1;

    printf("Enter 2nd subject mark: ");
    scanf("%f",&info.sub2);

    if(info.sub2>info.sub1)
        max = info.sub2;


    printf("Enter 3rd subject mark: ");
    scanf("%d",&info.sub3);

    if(info.sub3>info.sub2)
        max = info.sub3;

    total = info.sub1+info.sub2+info.sub3;

    printf("ID: %d\nTotal marks: %.2f \nHighest marks: %.2f",info.id,total,max);






}





3.



struct employee{
    int id;
    int age;
    float salary;
};


float highest(struct employee e[], int N){

    int i;
    float max;
    max = e[0].salary;
    for(i=1;i<N;i++){
        if(e[i].salary>max)
           max = e[i].salary;
    }
    return max;

}

main(){


    int N,i;
    float maxSalary;

    printf("Enter the number of employees: ");
    scanf("%d",&N);

    struct employee e[N];

    for(i=0;i<N;i++){
            printf("\nEnter no. %d employee ID: ",i+1);
            scanf("%d",&e[i].id);

            printf("Enter no. %d employee age: ",i+1);
            scanf("%d",&e[i].age);

            printf("Enter no. %d employee salary: ",i+1);
            scanf("%f",&e[i].salary);

    }

    maxSalary = highest(e,N);


    printf("%.2f",maxSalary);


}