Heapify a vector
0 likes • Nov 19, 2022 • 0 views
C++
Loading...
More C++ Posts
#include <iostream>#include <fstream>#include <string>#include <cstring>using namespace std;//This program makes a new text file that contains all combinations of two letters.// aa, ab, ..., zy, zzint main(){string filename = "two_letters.txt";ofstream outFile;outFile.open(filename.c_str());if(!outFile.is_open()){cout << "Something's wrong. Closing..." << endl;return 0;}for(char first = 'a'; first <= 'z'; first++){for(char second = 'a'; second <= 'z'; second++){outFile << first << second << " ";}outFile << endl;}return 0;}
#include <iostream>#include <cstring>int main(int argc, char** argv){//With decimalif(strstr(argv[1], ".") != nullptr){int i = 0;//Skip i to first non 0 digitwhile(argv[1][i] < '1' || argv[1][i] > '9') ++i;//If digit comes before decimalif((argv[1] + i) < strstr(argv[1], ".")){ //Good example of pointer arithmeticstd::cout << strlen(argv[1] + i) - 1 << std::endl; //Another good example}else{//If digit is after decimalstd::cout << strlen(argv[1] + i) << std::endl;}}else{//Without decimalint m = 0;int i = 0;while(argv[1][i] < '1' || argv[1][i] > '9') ++i; //In case of some number like 0045for(; argv[1][i] != '\0'; ++i){if(argv[1][i] >= '1' && argv[1][i] <= '9') m = i + 1;}std::cout << m << std::endl;}return 0;}
// Iterative C++ program to// implement Stein's Algorithm//#include <bits/stdc++.h>#include <bitset>using namespace std;// Function to implement// Stein's Algorithmint gcd(int a, int b){/* GCD(0, b) == b; GCD(a, 0) == a,GCD(0, 0) == 0 */if (a == 0)return b;if (b == 0)return a;/*Finding K, where K is thegreatest power of 2that divides both a and b. */int k;for (k = 0; ((a | b) & 1) == 0; ++k){a >>= 1;b >>= 1;}/* Dividing a by 2 until a becomes odd */while ((a & 1) == 0)a >>= 1;/* From here on, 'a' is always odd. */do{/* If b is even, remove all factor of 2 in b */while ((b & 1) == 0)b >>= 1;/* Now a and b are both odd.Swap if necessary so a <= b,then set b = b - a (which is even).*/if (a > b)swap(a, b); // Swap u and v.b = (b - a);} while (b != 0);/* restore common factors of 2 */return a << k;}// Driver codeint main(){int a = 12, b = 780;printf("Gcd of given numbers is %d\n", gcd(a, b));return 0;}
#include <iostream>using namespace std;int main(){cout << "Hello, World!" << endl;return 0;}
#include <iostream>#include <cstring>#include <unistd.h>#include <sys/utsname.h>int main() {char newHostname[] = "newhostname"; // Replace with the desired hostnameif (sethostname(newHostname, strlen(newHostname)) == 0) {std::cout << "Hostname set to: " << newHostname << std::endl;// Optionally, update the /etc/hostname file to make the change permanentFILE *hostnameFile = fopen("/etc/hostname", "w");if (hostnameFile != NULL) {fprintf(hostnameFile, "%s\n", newHostname);fclose(hostnameFile);} else {perror("Failed to update /etc/hostname");}} else {perror("Failed to set hostname");}return 0;}
#include <iostream>#include <vector>#include <limits>#define DEBUG_TRIAL falseclass Trial{public:const size_t HEIGHT;std::string record;//Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.//Eggs is the eggs remaining.//Start is the bottom floor.//End is one above the top floor.const size_t BREAKING_HEIGHT;size_t eggs;size_t start;size_t end;size_t floorsLeft(){return (end-start);}size_t middle(){return start + (floorsLeft()/2UL);}size_t drops = 0;Trial(const size_t BREAKING_HEIGHT, size_t eggs, size_t start, size_t end): BREAKING_HEIGHT(BREAKING_HEIGHT), eggs(eggs), start(start), end(end), HEIGHT(end), record(end, '_'){record[BREAKING_HEIGHT] = 'B'; //Marking the breaking point}bool foundAnswer(){return ((record[0] == 'X') || (record.find("OX")!=std::string::npos));}//returns true if the egg broke.//height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.bool drop(size_t height){#if DEBUG_TRIALstd::cout << "Start: " << start << ". End: " << end << ". Floors Left: " << floorsLeft() << ". Middle Index: " << middle() << std::endl;#endifdrops++;bool cracked = height >= BREAKING_HEIGHT;if(cracked) --eggs;//Update the recordrecord[height] = (height >= BREAKING_HEIGHT)? 'X' : 'O';#if DEBUG_TRIAL//Print the recordstd::cout << record << std::endl;#endifreturn cracked;}size_t nowWhat(){if(foundAnswer()){return drops;}else if(eggs <= 0){ //Ran out of eggsthrow "Algorithm failed! No more eggs!";return 1UL;}else if(eggs > 1){return wrecklessSearch();}else{return safeSearch();}}size_t safeSearch(){if(drop(start)){--end;}else{++start;}return nowWhat();}size_t wrecklessSearch(){//If the egg breaksif(drop(middle())){end -= (floorsLeft()/2UL);}else{ //egg doesn't crackstart += (floorsLeft()/2UL);}return nowWhat();}//returns the amount of drops needed to find the answersize_t search(){return nowWhat();}};//Height is the height of the building in floors.//Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.//Eggs is the eggs given.//returns the amount of drops needed to find the answersize_t search(const size_t height, const size_t BREAKING_HEIGHT, size_t eggs){Trial trial(BREAKING_HEIGHT, eggs, 0, height);return trial.search();}class TrialStats {public:size_t min = std::numeric_limits<size_t>::max();size_t max = 0;double mean = -1.0;void printStats(){// Print the resultsstd::cout << "Minimum drops: " << min << std::endl;std::cout << "Maximum drops: " << max << std::endl;std::cout << "Mean drops: " << mean << std::endl;}};//Benchmarks all the possible breaking points of a single building height with a number of eggs.TrialStats trial(const size_t HEIGHT, const size_t eggs){TrialStats stats;int totaldrops = 0;//Test every possible breaking point//Breaking height is the index of the floor, so 0 is the bottom floor, height-1 is the top floor.for (int breakingHeight = 0; breakingHeight < HEIGHT; ++breakingHeight) {size_t drops = search(HEIGHT, breakingHeight, eggs);stats.min = std::min(stats.min, drops);stats.max = std::max(stats.max, drops);totaldrops += drops;}// Calculate the mean number of dropsstats.mean = static_cast<double>(totaldrops) / HEIGHT;return stats;}//Benchmarks a single building height from 1 egg to MAX_EGGSvoid testTower(const size_t height, const size_t MAX_EGGS){//Drop every amount of eggs that you'd need.for (int eggs = 1; eggs <= MAX_EGGS; ++eggs) {std::cout << "Building height: " << height << ". Num eggs: " << eggs << std::endl;TrialStats stats = trial(height, eggs);stats.printStats();std::cout << std::endl << std::endl;}}//Benchmarks all buildings from 0 to MAX_HEIGHTvoid benchmark(const size_t MAX_HEIGHT){const size_t MAX_EGGS = 2;//Test every buildingfor (size_t height = 1; height <= MAX_HEIGHT; ++height) {testTower(height, std::min(height, MAX_EGGS));}}int main() {constexpr size_t MAX_HEIGHT = 36;benchmark(MAX_HEIGHT);return 0;}