Daily: Cutting a Wall
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//From https://create.arduino.cc/projecthub/abhilashpatel121/easyfft-fast-fourier-transform-fft-for-arduino-9d2677#include <cmath>#include <iostream>const unsigned char sine_data[] = { //Quarter a sine wave0,4, 9, 13, 18, 22, 27, 31, 35, 40, 44,49, 53, 57, 62, 66, 70, 75, 79, 83, 87,91, 96, 100, 104, 108, 112, 116, 120, 124, 127,131, 135, 139, 143, 146, 150, 153, 157, 160, 164,167, 171, 174, 177, 180, 183, 186, 189, 192, 195, //Paste this at top of program198, 201, 204, 206, 209, 211, 214, 216, 219, 221,223, 225, 227, 229, 231, 233, 235, 236, 238, 240,241, 243, 244, 245, 246, 247, 248, 249, 250, 251,252, 253, 253, 254, 254, 254, 255, 255, 255, 255};float sine(int i){ //Inefficient sineint j=i;float out;while(j < 0) j = j + 360;while(j > 360) j = j - 360;if(j > -1 && j < 91) out = sine_data[j];else if(j > 90 && j < 181) out = sine_data[180 - j];else if(j > 180 && j < 271) out = -sine_data[j - 180];else if(j > 270 && j < 361) out = -sine_data[360 - j];return (out / 255);}float cosine(int i){ //Inefficient cosineint j = i;float out;while(j < 0) j = j + 360;while(j > 360) j = j - 360;if(j > -1 && j < 91) out = sine_data[90 - j];else if(j > 90 && j < 181) out = -sine_data[j - 90];else if(j > 180 && j < 271) out = -sine_data[270 - j];else if(j > 270 && j < 361) out = sine_data[j - 270];return (out / 255);}//Example data://-----------------------------FFT Function----------------------------------------------//float* FFT(int in[],unsigned int N,float Frequency){ //Result is highest frequencies in order of loudness. Needs to be deleted./*Code to perform FFT on arduino,setup:paste sine_data [91] at top of program [global variable], paste FFT function at end of programTerm:1. in[] : Data array,2. N : Number of sample (recommended sample size 2,4,8,16,32,64,128...)3. Frequency: sampling frequency required as input (Hz)If sample size is not in power of 2 it will be clipped to lower side of number.i.e, for 150 number of samples, code will consider first 128 sample, remaining sample will be omitted.For Arduino nano, FFT of more than 128 sample not possible due to mamory limitation (64 recomended)For higher Number of sample may arise Mamory related issue,Code by ABHILASHContact: [email protected]Documentation:https://www.instructables.com/member/abhilash_patel/instructables/2/3/2021: change data type of N from float to int for >=256 samples*/unsigned int sampleRates[13]={1,2,4,8,16,32,64,128,256,512,1024,2048};int a = N;int o;for(int i=0;i<12;i++){ //Snapping N to a sample rate in sampleRatesif(sampleRates[i]<=a){o = i;}}int in_ps[sampleRates[o]] = {}; //input for sequencingfloat out_r[sampleRates[o]] = {}; //real part of transformfloat out_im[sampleRates[o]] = {}; //imaginory part of transformint x = 0;int c1;int f;for(int b=0;b<o;b++){ // bit reversalc1 = sampleRates[b];f = sampleRates[o] / (c1 + c1);for(int j = 0;j < c1;j++){x = x + 1;in_ps[x]=in_ps[j]+f;}}for(int i=0;i<sampleRates[o];i++){ // update input array as per bit reverse orderif(in_ps[i]<a){out_r[i]=in[in_ps[i]];}if(in_ps[i]>a){out_r[i]=in[in_ps[i]-a];}}int i10,i11,n1;float e,c,s,tr,ti;for(int i=0;i<o;i++){ //ffti10 = sampleRates[i]; // overall values of sine/cosine :i11 = sampleRates[o] / sampleRates[i+1]; // loop with similar sine cosine:e = 360 / sampleRates[i+1];e = 0 - e;n1 = 0;for(int j=0;j<i10;j++){c=cosine(e*j);s=sine(e*j);n1=j;for(int k=0;k<i11;k++){tr = c*out_r[i10 + n1]-s*out_im[i10 + n1];ti = s*out_r[i10 + n1]+c*out_im[i10 + n1];out_r[n1 + i10] = out_r[n1]-tr;out_r[n1] = out_r[n1]+tr;out_im[n1 + i10] = out_im[n1]-ti;out_im[n1] = out_im[n1]+ti;n1 = n1+i10+i10;}}}/*for(int i=0;i<sampleRates[o];i++){std::cout << (out_r[i]);std::cout << ("\t"); // un comment to print RAW o/pstd::cout << (out_im[i]); std::cout << ("i");std::cout << std::endl;}*///---> here onward out_r contains amplitude and our_in conntains frequency (Hz)for(int i=0;i<sampleRates[o-1];i++){ // getting amplitude from compex numberout_r[i] = sqrt(out_r[i]*out_r[i]+out_im[i]*out_im[i]); // to increase the speed delete sqrtout_im[i] = i * Frequency / N;std::cout << (out_im[i]); std::cout << ("Hz");std::cout << ("\t"); // un comment to print freuency binstd::cout << (out_r[i]);std::cout << std::endl;}x = 0; // peak detectionfor(int i=1;i<sampleRates[o-1]-1;i++){if(out_r[i]>out_r[i-1] && out_r[i]>out_r[i+1]){in_ps[x] = i; //in_ps array used for storage of peak numberx = x + 1;}}s = 0;c = 0;for(int i=0;i<x;i++){ // re arraange as per magnitudefor(int j=c;j<x;j++){if(out_r[in_ps[i]]<out_r[in_ps[j]]){s=in_ps[i];in_ps[i]=in_ps[j];in_ps[j]=s;}}c=c+1;}float* f_peaks = new float[sampleRates[o]];for(int i=0;i<5;i++){ // updating f_peak array (global variable)with descending orderf_peaks[i]=out_im[in_ps[i]];}return f_peaks;}//------------------------------------------------------------------------------------////main.cppint data[64]={14, 30, 35, 34, 34, 40, 46, 45, 30, 4, -26, -48, -55, -49, -37,-28, -24, -22, -13, 6, 32, 55, 65, 57, 38, 17, 1, -6, -11, -19, -34,-51, -61, -56, -35, -7, 18, 32, 35, 34, 35, 41, 46, 43, 26, -2, -31, -50,-55, -47, -35, -27, -24, -21, -10, 11, 37, 58, 64, 55, 34, 13, -1, -7};int main(){const unsigned int SAMPLE_RATE = 48*1000; //48khzauto result = FFT(data,64,SAMPLE_RATE);std::cout << result[0] << " " << result[1] << " " << result[2] << " " << result[3] << std::endl;delete[] result;return 0;}
//Leif Messinger//Finds all sets of 5 5 letter words that don't have duplicate letters in either themselves or each other.//First it reads the words in and puts them in groups of their bitmasks//After that, we recurse on each group. Before doing that, we remove the group from the set of other groups to check it against.#include <cstdio> //getchar, printf#include <cassert> //assert#include <vector>#include <set>#include <algorithm> //std::copy_if#include <iterator> //std::back_inserter#define CHECK_FOR_CRLF true#define MIN_WORDS 5#define MAX_WORDS 5#define WORD_TOO_LONG(len) (len != 5)const unsigned int charToBitmask(const char bruh){assert(bruh >= 'a' && bruh <= 'z');return (1 << (bruh - 'a'));}void printBitmask(unsigned int bitmask){char start = 'a';while(bitmask != 0){if(bitmask & 1){putchar(start);}bitmask >>= 1;++start;}}//Pointer needs to be deletedconst std::set<unsigned int>* getBitmasks(){std::set<unsigned int>* bitmasksPointer = new std::set<unsigned int>;std::set<unsigned int>& bitmasks = (*bitmasksPointer);unsigned int bitmask = 0;unsigned int wordLength = 0;bool duplicateLetters = false;for(char c = getchar(); c >= 0; c = getchar()){if(CHECK_FOR_CRLF && c == '\r'){continue;}if(c == '\n'){if(!(WORD_TOO_LONG(wordLength) || duplicateLetters)) bitmasks.insert(bitmask);bitmask = 0;wordLength = 0;duplicateLetters = false;continue;}if((bitmask & charToBitmask(c)) != 0) duplicateLetters = true;bitmask |= charToBitmask(c);++wordLength;}return bitmasksPointer;}void printBitmasks(const std::vector<unsigned int>& bitmasks){for(unsigned int bruh : bitmasks){printBitmask(bruh);putchar(','); putchar(' ');}puts("");}//Just to be clear, when I mean "word", I mean a group of words with the same letters.void recurse(std::vector<unsigned int>& oldBitmasks, std::vector<unsigned int> history, const unsigned int currentBitmask){//If there's not enough words leftif(oldBitmasks.size() + (-(history.size())) + (-MIN_WORDS) <= 0){//If there's enough wordsif(history.size() >= MIN_WORDS){//Print the listprintBitmasks(history);}return;//To make it faster, we can stop it after 5 words too}else if(history.size() >= MAX_WORDS){//Print the listprintBitmasks(history);return;}//Thin out the array with only stuff that matches the currentBitmask.std::vector<unsigned int> newBitmasks;std::copy_if(oldBitmasks.begin(), oldBitmasks.end(), std::back_inserter(newBitmasks), [¤tBitmask](unsigned int bruh){return (bruh & currentBitmask) == 0;});while(newBitmasks.size() > 0){//I know this modifies 'oldBitmasks' too. It's intentional.//This makes it so that the word is never involved in any of the child serches or any of the later searches in this while loop.const unsigned int word = newBitmasks.back(); newBitmasks.pop_back();std::vector<unsigned int> newHistory = history;newHistory.push_back(word);recurse(newBitmasks, newHistory, currentBitmask | word);}}int main(){const std::set<unsigned int>* bitmasksSet = getBitmasks();std::vector<unsigned int> bitmasks(bitmasksSet->begin(), bitmasksSet->end());delete bitmasksSet;recurse(bitmasks, std::vector<unsigned int>(), 0);return 0;}
/*Good morning! Here's your coding interview problem for today.This problem was asked by Stripe.Given an array of integers, find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can contain duplicates and negative numbers as well.For example, the input [3, 4, -1, 1] should give 2. The input [1, 2, 0] should give 3.You can modify the input array in-place.*/#include <iostream>using namespace std;int calcMissing(int* input, int size){int sum = 0;int n = 1; //add one to account for missing valuefor(int i = 0; i < size; i++){if(input[i] > 0){sum += input[i];n++;}}//If no numbers higher than 0, answer is 1if(sum == 0)return 1;return (n*(n+1)/2) - sum; //Formula is expectedSum - actualSum/* expectedSum = n*(n+1)/2, the formula for sum(1, n) */}int main(){cout << calcMissing(new int[4]{3, 4, -1, 1}, 4) << endl;cout << calcMissing(new int[3]{1, 2, 0}, 3) << endl;//No positive numberscout << calcMissing(new int[1]{0}, 1) << endl;}
#include <iostream>#include <cmath>#include <string.h>using namespace std;int main() {string tickerName;int numOfContracts;float currentOptionValue;cout << "Enter a stock ticker: ";getline(cin, tickerName);cout << "Enter the current number of " << tickerName << " contracts you are holding: ";cin >> numOfContracts;cout << "Enter the current price of the option: ";cin >> currentOptionValue;cout << "The value of your " << tickerName << " options are: $" << (currentOptionValue * 100.00) * (numOfContracts);cout << endl;return 0;}
#define NUM_BITS 8#include <iostream>struct Number{int num : NUM_BITS;Number(){}Number(const int& bruh){num = bruh;}operator int() const { return num; }Number& operator=(const int& bruh){num = bruh;return (*this);}};using namespace std;bool isNegative(const int& num){//This gets the bitwise and of num and 10000000000000000000000000000000//This implicit casts to bool, which means (num & (1 << 31)) != 0return (num & (1 << 31));}void printBinaryNumber(const int& num, const int numBits){for(int i = numBits; i > 0; --i){//8..1int bitMask = 1 << (i-1);if(num & bitMask){ //Test the bitcout << '1';}else{cout << '0';}}}void printCarryBits(const int& a, const int& b, const int numBits){int answer = 0;bool carry = false;for(int i = 0; i < numBits; ++i){//8..1int bitMask = 1 << i;bool aBit = a & bitMask;bool bBit = b & bitMask;if(aBit && bBit || aBit && carry || bBit && carry){ //Carry bit is true nextif(carry)answer |= bitMask;carry = true;}else{if(carry)answer |= bitMask;carry = false;}}printBinaryNumber(answer, 8);}void printBorrowBits(const int& a, const int& b, const int numBits){int answer = 0;bool carry = false;for(int i = 0; i < numBits; ++i){//8..1int bitMask = 1 << i;bool aBit = a & bitMask;bool bBit = b & bitMask;if((!(aBit ^ carry)) && bBit){ //Carry bit is true nextif(carry)answer |= bitMask;carry = true;}else{if(carry)answer |= bitMask;carry = false;}}printBinaryNumber(answer, 8);}void doProblem(const int& a, const int& b, const char& sign, const int& result, const int& numBits){if(sign == '+'){cout << ' '; printCarryBits(a, b, numBits); cout << endl;}else{cout << ' '; printBorrowBits(a, b, numBits); cout << endl;}cout << ' '; printBinaryNumber(a, numBits); cout << endl;cout << sign; printBinaryNumber(b, numBits); cout << endl;cout << "----------" << endl;cout << ""; printBinaryNumber(result, numBits + 1); cout << " = " << result;cout << endl;}int main(){Number a = 0b110;Number b = 0b011;cout<< a << endl << b << endl;doProblem(a, b, '+', a + b, NUM_BITS);doProblem(a, b, '-', a - b, NUM_BITS);doProblem(-a, b, '+', -a + b, NUM_BITS);doProblem(a, b, '-', -a - b, NUM_BITS);return 0;}
#include<iostream>using namespace std;const int rows = 8;const int cols = 8;char chessboard[rows][cols];void setBoard(char chessboard[][cols]);void printBoard(char chessboard[][cols]);void setBoard(char chessboard[][cols]) {for(int i = 0; i < rows; i++) {for(int j = 0; j < cols; j++) {if(i % 2 == 0 && j % 2 == 0) {chessboard[i][j] = 'x';} else {if(i % 2 != 0 && j % 2 == 1) {chessboard[i][j] = 'x';} else {chessboard[i][j] = '-';}}}}return;}void printBoard(char chessboard[][cols]) {for(int i = 0; i < rows; i++) {for(int j = 0; j < cols; j++) {cout << chessboard[i][j] << " ";}cout << endl;}return;}int main(int argc, char const *argv[]){setBoard(chessboard);printBoard(chessboard);return 0;}