Question

I need help with C, please don't copy other answers!!

Thanks

Declare a structure to represent a circle. Each circle stores information about the center and the radius. Center is represents with x and y coordinates. Both center and radius uses doubles. Allocate an array of 502 circle pointers and dynamically allocated memory to store a circle pointed by each array entry. Randomly generate circles using the following function. double rand_ float (double a, double b) {return ((double) rand()/RAND_MAX) * (b-a) + a;} We want all the circle to fit an area of 1000 times 1000. So, x and y coordinates are randomly selected from (100,000) and radius is randomly selected from (0.100) using above function. After you insert the random circles, find the circle with the largest area and print the information for this circle. You can use 3.14 for PI and area of a circle is given as PI * radius * radius. Don't forget to free the pointers when you are done with the array. Use Valerian to find any memory leads. Sample execution is given below.

Answer 1

Dear Student,

Here is the program..

NOTE: Please note that the following program has been tested on ubuntu 14.04 system and compiled under gcc compiler.

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program...

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//Header files DEclaration

#include<stdio.h>

#include<stdlib.h>

#include<math.h>

//Structure Declarartion

struct Circle

{

//structure member declarartion
double x; //x coordinate

double y; //y coordinate

double r; //radius

};

//function Prototype Declaration

double rand_float(double a, double b);

//starting of main function

int main()

{

//Varibale Data Type declaration

int i;

double Area[100];

double PI = 3.14, x, y, max, r;

struct Circle *C;

//Memory allocation for 50 array

C = (double*)malloc(sizeof(struct Circle) * 50);

//Call to rand_float function 50 times to obtain the value of r, x, y

for(i=1;i<=50;i++)

{

C[i].x = rand_float(100, 900);

C[i].y = rand_float(100, 900);

C[i].r = rand_float(0, 100);

//Calculation of Area;

Area[i] = PI* pow(C[i].r, 2);

}

//Display all dimensions for 50 circles and the resultant area

for(i=1;i<=50;i++)

{

printf("CIrcle %d, Center: x = %lf, y = %lf, radius = %lf, Area = %lf\n",i, C[i].x, C[i].y, C[i].r, Area[i]);

}

//finding Maximum Area;

for(i = 1; i<=50;i++)

{

if(Area[1] > Area[i])

{

max = Area[i];

x = C[i].x;

y = C[i].y;

r = C[i].r;

}

}

printf("\n");

//Display Max area

printf("Circle withe largest area (%lf) has center (%lf, %lf) and radius %lf\n",max, x, y, r);

printf("\n");

free(C);

return 0;

}

//function defination to return the x, y, r;

double rand_float(double a, double b)

{

return ((double)rand()/RAND_MAX) * (b-a) + a;

}

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Here i have attached the output of the program as a screen shot...

Output:

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nirnalsharma@ubuntu:-/HomeworkLib_solutions$./a.out Circle 1, Center: x 772.150174, y 415.506341, radius = 78.309922, Area = 19255.873979 Circle 2, Center: x = 738 . 752027, y 829.317886 , radius 19.755137, Area 1225.433466 Circle 3, Center: x 368 . 178205, y = 714.583676, radius 27.777471, Area 2422·786θθ5 Circle 4, Center: x = 543.175965, y = 481.917641, radius = 62.887092, Area = 12418.029296 Circle 5, Center: x = 391.827578, y = 510.720728 , radius = 95.222973, Area = 28471.681514 Circle 6, Center: x 832.956054, y = 608.569382, radius 71.729693, Area = 16155.767388 Circle 7, Center : x = 213 . 282044, y 585.575101, radius 1.630057, Area 8.343251 Circle 8, Center: x = 294 . 309417, y = 209 . 785261, radius 80.417675, Area = 20306.3879 14 Circle 9, Center: x = 225.343271, y 420.755515, radius = 12.979045, Area = 528.950586 Circle 10, Center: x = 187 . θ47042, y 899.139614, radius 21.825691, Area 1495.772809 Circle 11, Center: x = 510.345916, y = 771.289788 , radius = 61.263983, Area = 11785.285525 CIrcle 12, Center:x 336.825294, y 610.041814, radius 52.428719, Area8631.139611 Circle 13, Center: x = 494.866390, y = 878 . 22θθ 19 , radius 29.251678 , Area 2686.774572 Circle 14, Center: x = 717.086158, y = 521.395983, radius = 76.991384 , Area = 18612.893700 Circle 15, Center: x = 420.182898, y = 813.223562, radius = 28.331475, Area 2529.391503 Circle 16, Center: x = 381.966678, y = 746.179616, radius = 91.902647 , Area = 26520.743319 CIrcle 17, Center: x 155.804221, y 859.461660, radius 52.599535, Area8687.472805 Circle 18, Center: x = 168.844678, y = 253.771077, radius = 66 . 322693, Area - 13811.916641 Circle 19, Center: x = 812.186082, y = 379.114348 , radius = 6.417132 , Area = 129.303894 Circle 20, Center: x 116.018439, y = 466. 161390, radius = 6.309584 , Area = 125.006063 Circle 21, Center: x = 290 . 623963, y = 876.507305, radius = 90 . 220807 , Area = 25558 . 953407 Circle 22, Center: x 780 . 735829, y 313.332600, radius 53.976θ34, Area 9148 . 114478 (Circle 23, Center: x = 488 . 165581, y 708.198989, radius = 51.253536 , Area 8248.544484 Circle 24, Center: x = 634.179009, y = 525.285147, radius = 3.928034 , Area = 48.448485 i-Circle 25, Center: x - 450. 110677, y - 845.468045, radius 93.080980 , Area 27205.175879 Circle 26, Center: x = 676.761874, y = 327.434722, radius = 73.853431, Area = 17126.594137 CIrcle 27, Center:x611.983053, y383.238944, radius- 68.786139, Area14857.013376 Circle 28, Center: x = 232.779333, y = 452.083622, radius = 88.007524 , Area - 24320 .318034 Circle 29, Center: x = 763.360875, y = 364.269704 , radius = 22.896817, Area = 1646.189693 Circle 30, Center: x 814.697932, y = 380.288143, radius = 68.666991, Area 14805.588678 Circle 31, Center: x = 865.174602, y = 570.912107, radius = 65.730404 , Area = 13566 . 326052 circle 32, Center: x - 786. 941661, y - 451.647936, radtus - 92.396979, Area 26806.813364 Circle 33, Center: x = 418.749333, y - 751.813517, radius 68 . 421853, Area - 14700 . 066696 circle 34, center: x = 828.777625, y = 485.992525, radius = 21.582496 , Area = 1462.624965 Circle 35, Center: x = 860 .201899, y = 836. 102603 , radius = 14.766001, Area 684.629271 circle 36, center: x = 804 . 849736, y = 612.864477 , radius = 43.195342, Area = 5858.729924 CIrcle 37, Center: x 595.677187, y 324.847530, radius78.600210, Area19398.897960 Circle 38 , Center: x = 345.966299, y _ 457.626863, radius = 22.610663, Area = 1605. 30θθ66 Circle 39 , Center: x = 250.026488, y = 320.987738 , radius = 55.644376, Area = 9722.371099 CIrcle 40, Center: x433.201024, y- 235.685669, radius-90.680393, Area 25820.011958

circle 41, center: x = 182.536951, y = 200.860271, radius = 49.544407, Area = 7707.595446 Circle 42, Center: x 788 . 380183, y 887.801332, radius 93.500399 , Area 27450.899083 Circle 43, Center: x = 647.556013, y = 406.550665, radius = 74.977088, Area = 17651.710210 Circle 44 , Center: x 394.930833, y = 335.328290, radius 23.226154, Area 1693.886261 Circle 45, Center: x = 567 . 59θ801, y 295.530189, radius = 15.238979, Area 729.191168 Circle 46 , Center: x = 685. 718813, y = 200 .379924, radius = 79.347039, Area = 19769.291067 Circle 47, Center : x 231.281547, y 696.057111, radius = 7.452980, Area 174 . 417303 Circle 48 , Center: x = 860 .083225, y 142.023410, radius = 52.156338, Area = 8541.690477 circle 49, center: x = 240.968525, y = 292.049898, radius 79.779805, Area = 19985.526371 Circle 50, Center : x 686 .123529, y 625.250922, radius 96 . 740514, Area 29386.402844 Circle withe largest area (8541.690477) has center (860.083225, 142.023410) and radius 52.156338

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To check the memory leak we use the valgrind command.

below command i have used to check the memory leak in my case..

valgrind --tool=memcheck ./a.out          (here ./a.out is the executable file)

here i have attached the output of the valgrind command. In the last screen shot you can see that no memory leak found.

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nirmalsharma@ubuntu:-/HomeworkLib solutionss valgrind tool-mencheck./a.out 3550 Mencheck, a menory error detector 3550Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al. 3550 Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info 3550 Command: ./a.out 3550- =:3550== Invalid write of size 8 3550= at 0x400804: main (in /home/nirnalsharna/HomeworkLibーsolutions/a.out) ==3550== Address 0x55054f0 1s θ bytes after a block of size 1,200 alloc'd ==3550== at 0x4C 2AB80: malloc (in /usr/lib/valgrind/vgpreload-memcheck-and64-linux . so) 3550by 0x400783: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) 3550- -3550Invalid write of size 8 3550at 0x400871: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) =:3550== Address 0x55054f8 is 8 bytes after a block of size 1,200 alloc 'd malloc (in /usr/lib/valgrind/vgpreloadne check-and64-linux. so) 3550= 3550 by 0x400783: main (in /home/nirmalsharma/HomeworkLib_solutions/a.out) at θΧ4C2AB80: ==3550== 3550Invalid write of size 8 =:3550== at 0x4008CA: main (in /home/nirnalsharma/HomeworkLib-solutions/a·out) 3550Address ox5505500 is 16 bytes after a block of size 1,200 alloc'd =3550== 3550 by 0x400783: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) -3550-- -3550 Invalid read of size 8 at 0x4C2AB80: alloc (in /usr/lib/valgrind/vgpreload_aencheck-and64-linux . so) 3550= at 0x4008F1: nain (in /hone/nirma1sharma/HomeworkLib-solutions/a.out) =3550== Address 0x5505500 is 16 bytes after a block of size 1,200 alloc'd に=3550== at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload-memcheck-and64-linux . so) 3550by 0x400783: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) 3550-- Circle 1, Center: x 772.150174 , y 415.506341, radius 78.309922, Area 19255.873979 Circle 2, Center: x = 738.752027, y = 829.317886, radius 19.755137, Area = 1225.433466 Circle 3, Center: x 368.178205, y = 714.583676, radius = 27.777471, Area 2422.786005 Circle 4, Center: x = 543.175965, y 481.917641, radius 62.887092, Area = 12418 . Э29296 Circle 5, Center: x = 391.827578, y = 510.720728, radius = 95.222973, Area 28471.681514 Circle 6, Center: x 832.956054, y 688.569382, radius 71.729693, Area 16155.767388 Circle 7, Center: x = 213.282044 , y = 585.575101, radius 1.630057, Area = 8.343251 Circle 8, Center: x = 294 . 309417, y 209.785261, radius = 80.417675, Area 20306.387914 Circle 9, Center: x = 225.343271, y = 420.755515, radius 12.979845, Area = 528.950586 Circle 10, Center: x = 187.047042, y 899.139614, radius = 21.825691, Area = 1495.772809 icircle 11, center: x = 510.345916, y = 771.289788, radius 61.263983, Area 11785.285525

Circle 12, Center: x 336 . 825294, y 610.041814, radius = 52.428719, Area 8631.139611 Circle 13, Center: x 494.866390, y 878.2200 19 , radius 29.251678, Area 2686.774572 Circle 14, Center: x 717.086 158, y 521.395983, radius = 76.99 1384 , Area 18612.893700 CIrcle 15, Center: x 420.182898, y 813.223562, radius28.331475, Area2520.391503 Circle 16, Center : x 381.966678 , y = 746.1796 16, radius = 91.902647, Area 26520.743319 Circle 17, Center: x = 155.804221, y 859.46 1660 , radius = 52.599535, Area 8687.472805 Circle 18, Center: x 168.844678, y 253.771077, radius = 66.322693, Area 13811.916641 Circle 19, Center: x 812.186082, y 379.114348, radius 6.417132, Area 129.303894 Circle 20, Center: x 116.018439, y 466.161390, radius = 6.309584 , Area = 125.006063 Circle 21, Center: x 290.623963, y 876.507305, radius = 96.220807, Area = 25558.953407 circle 22, center: x = 780.735829, y = 313.332688, radius = 53.976034, Area = 9148.114478 Circle 23, Center: x = 488.165581, y = 708.198989, radius = 51.253536, Area = 8248.544484 circle 24, Center: x = 634.179889, y 525.285147, radius = 3.928034, Area = 48.448485 Circle 25, Center : x = 450. 110677, y 845.468045, radius = 93.080980, Area = 27205.175879 Circle 26, Center: x 676.761874, y = 327.434722, radius = 73.853431, Area = 17126.594137 Circle 27, Center: x 611.983053, y = 383.238944, radius = 68.786139, Area = 14857.013376 Circle 28, Center: x 232.779333, y = 452.083622, radius = 88.007524, Area = 24320.318034 Circle 29, Center: x = 763.368875, y = 364 . 269704, radius = 22.896817, Area = 1646.189693 Circle 30, Center: x 814.697932, y = 386.288143, radius = 68.666991, Area = 14805.588678 Circle 31, Center: x = 865.174602, y = 570 . 912107, radius = 65.730404 , Area = 13566.326052 circle 32, center: x = 786.941061, y = 451.647936, radius = 92.396979, Area = 26806.813364 :Circle 33, center: x = 418.749333, y = 751.813517, radius = 68.421853, Area = 14700.066696 circle 34, center: x = 828.777625, y = 485.992525, radius = 21.582496, Area = 1462.624965 Circle 35, Center: x 860 . 201899, y = 836.102603, radius = 14.766001, Area = 684.629271 circle 36, center: x = 804 . 849736, y = 612.864477, radius = 43.195342, Area = 5858.729924 Circle 37, Center: x 595.677187, y = 324.847530, radius = 78.600210, Area = 19398.897960 İCircle 38, Center: x = 345.966299, y 457.626863, radius = 22.610663, Area = 1605.300066 icircle 39, Center: x = 250.026488, y 320.987738, radius = 55.644376, Area = 9722.371099 Circle 40, Center: x = 433.201024, y = 235.685669 , radius = 90.680393, Area = 25820. O11958 |circle 41, Center: x = 182.536951, y 200.860271, radius = 49.544407, Area = 7767.595446 Circle 42, Center: x 708 . 380 183, y 887.801332, radius 93.500399, Area = 27450.899083 Circle 43, Center: x 647.556013, y 406.550665, radius = 74.977088, Area = 17651.710210 Circle 44 , Center: x 394.930833, y 335.328290 , radius = 23.226154, Area = 1693.886261 Circle 45, Center: x 567.590801, y 295.530189 , radius :: 15.238979, Area 729.191168 Circle 46, Center: x 685.718813, y 200.379924 , radius 79 . 347039, Area 19769.291067 Circle 47, Center: x 231.281547, y 696.057111, radius 7.452980, Area 174 . 417303 Circle 48, Center: x 860.083225, y 142.023410, radius = 52.156338, Area 8541.690477 CIrcle 49, Cente 240.968 525, y = 292.049898 , radiu 79.779805, Area = 19985.526371 -3550=-Invalid read of size 8 at 0x400991: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) 200 alloc'd 50== Add 0x5505500 is 16 bytes af a block of size

==3550== at 0x4C2AB80 : malloc (in /usr/lib/valgrind/vgpreload-memcheck-and64-linux . so) 3550 by 0x400783: main (in /hone/nirmalsharma/HomeworkLib_solutions/a.out) 3550 3550-Invalid read of ==3550= at 0x4009BB: size 8 main (in /home/nírmalsharma/HomeworkLib-solutions/a·out) 3550 Address 0x55054f8 is 8 bytes after a block of size 1,20o alloc'd :==3550= at 0x4C2AB80 : malloc (in /usr/lib/valgrind/vgpreload-mencheck-and64-linux . so) ==3550- by 0x400783: main (in /home/nírmalsharma/HomeworkLib-solutions/a·out) 3550 -3550Invalid read of size 8 ー=3550== at 0x4009DF: main (in /home/nírmaïsharma/HomeworkLib-solutions/a.out) -=3550== Address 0x55054f0 ís θ bytes after a block of size 1,200 alloc' d ー=3550= at 0x4C2AB80 : malloc (in /usr/lib/valgrind/vgpreload-mencheck-and64-linux . so) 3550 3550 by 0x400783: main (in /home/nirmalsharma/HomeworkLib_solutions/a.out) CIrcle 50, Center: x - 686.123529, y 625.250922, radius - 96.740514, Area 29386.402844 Circle withe largest area (8541.690477) has center (860.083225, 142.023410) and radius 52.156338 ==3550== HEAP SUMMARY: in use at exit : 0 bytes in blocks 3550- total heap usage : 1 allocs, 1 frees, 1,200 bytes allocated 3550-- ==3550== All heap blocks were freed -- no ïeaks are possible 3550-- 3550 For counts of detected and suppressed errors, rerun with: -v ==3550== ERROR SUMMARY: 7 errors from 7 contexts (suppressed : from 0) nirmalsharma@ubuntu:-/HomeworkLib solutionss

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Kindly Check and Verify Thanks...!!!