The idea that, for each pair of devices v and w, there’s a strict dichotomy between being “in range” or “out of range” is a simplified abstraction. more accurately, there’s a power decay function f (·) that specifies, for a pair of devices at distance δ, the signal strength f(δ) that they’ll be able to achieve on their wireless connection. (we’ll assume that f (δ) decreases with increasing δ.) we might want to build this into our notion of back-up sets as follows: among the k devices in the back-up set of v, there should be at least one that can be reached with very high signal strength, at least one other that can be reached with moderately high signal strength, and so forth. more concretely, we have values p1 ≥ p2 ≥ . . ≥ pk, so that if the back-up set for v consists of devices at distances d1≤d2≤≤dk, thenweshouldhavef(dj)≥pj foreachj. give an algorithm that determines whether it is possible to choose a back-up set for each device subject to this more detailed condition, still requiring that no device should appear in the back-up set of more than b other devices. again, the algorithm should output the back-up sets themselves, provided they can be found.\

Awell-diversified portfolio needs about 20-25 stocks from different categories is this true or false?

Rafael needs to add a title row to a table that he has inserted in word. what should he do? use the alignment options. use the merge and center option for all the cells in the top row. use the merge and center option on the first two cells in the top row. none of the above

Computer security/cybersecurity1) each of the following code fragments contains a number of security vulnerabilities. for each fragment, identify these security vulnerabilities and, for each vulnerability, discuss at least one way that it could be improved. note that in your discussion of how each vulnerability could be improved, you do not need to re-write a new version of the program in c; simply discuss your solution, either in pseudocode or in 1-2 sentences.a) /* file descriptor leak */#include #include int main(int argc, char *argv[]){ char *filepath = argv[0]; char *shellpath = argv[1]; file *passwords; passwords = fopen(filepath, "r"); /* read the password and do something with it */ /* . . */ /* fork and execute alternative shell */ execl(shellpath, "shell", null); }b)#include /* assume the following function is written for an electronic storefront. the user will enter the id of the item to be ordered, as well as the quantity of units that they would like to purchase. the program will then lookup the price for the price for the item using a predefined function, and return the total cost of the order.*/int gettotalcost(){ char itemid[9]; int price, unitsordered, cost; printf(" enter the 9-digit id of the item to be ordered: "); scanf("%s", & itemid); /* lookup the price according to the itemid */ price = getpricebyid(itemid); printf(" enter the quantity of units to be ordered: "); scanf("%d", & unitsordered); cost = price * unitsordered; return cost; }c)#include /* the following function is intended to return a user's full name by concatenating the user's first and last name into a single string and then returning that string. */char *getfullname(char *firstname, char *lastname, int max_len){ char fullname[max_len]; strcpy(fullname, firstname); strcat(fullname, " "); strcat(fullname, lastname); return fullname; }d)#include /* the following code snippet runs through the list of cli arguments entered and displays them to the console. */int main(int argc, char *argv[]){ int i; printf("you've entered the following arguments: "); for(i = 0; i < argc; i++){ print(argv[i]); printf("\n"); } /* */}