Advertisements In the following code, I erase an element (pair of integers) from a vector, and the size after deletion is decremented. But as you can see, printing the vector by index doesn’t look normal. I expect some out-of-range errors at runtime. Isn’t that correct? vector<pair<int, int>> v; v.push_back(make_pair(1, 2)); v.push_back(make_pair(3, 4)); v.push_back(make_pair(5, 6)); cout… Read More Erase and resize a vector

Advertisements Despite the numerous examples on internet I could not figure out this one: How to iterate over a Vector (which itself contains Vector of 2 String items) and return the second item? My attempt (returns true, I would like to get "the result" instead) fn main() { let data:Vec<Vec<&str>> = vec![vec!["b", "dummy"], vec!["c", "dummy"],vec!["r",… Read More Iterate over a Vector with condition and return the second item of Vector/Tuple

Advertisements I learned 2 ways of inserting elements into a vector. And I’ve been wondering which way is faster since I’m working with time limits. Method 1: int n; cin>>n; vector<int> v(n); for(int i = 0;i<n;i++){ cin>>v[i]; } Method 2: int n; cin>>n; vector<int> v; for(int i = 0;i<n;i++){ int x; cin>>x; v.push_back(x); } If… Read More Is it faster to use push_back(x) or using an index (capacity)?

Advertisements What is the more idiomatic way to sort a vector of strings by char? Example: Input: ["3r", "2n", "2s", "7r", "1s", "1s", "6r", "1s", "1n", "1n", "5n", "9n", "3r"] Desired output: ["1n", "1n", "2n", "5n", "9n, "3r", "3r", "6r", "7r", "1s", "1s", "1s", "2s"] First they need to be sorted on the second char… Read More How to sort a vector of strings by char in Rust?

Advertisements Problem: Write a code that changes the value of the 4th element of vector y to 6, then changes the value of last element to the same as 1st element and finally calculates the sum of all the elements. Attempted solution: y[4]<-6 y["last"]<- 1 sum(y) Can’t figure out what’s wrong with this… help is… Read More How to change the value of the last element to the same as 1st element?

Advertisements say I have the following list of vectors vectors=[(10,0),(-10,0),(0,10),(0,-10)] and I have the following random vector: vector=(200,-300) how can I get the vector from the list that is the most similar to the vector that I am inputting in python? >Solution : You can use scipy.spatial to find nearest neighbor. Eg: import numpy as… Read More how to fit random vector into list of vectors python

Advertisements Say I have a pair of vectors, one consisting of variable names and the other containing Booleans that determine whether the variables in the first vector should be treated as factors or not: a <- c("var1", "var2", "var3") b <- c(TRUE, FALSE, FALSE) Is there a way of automatically converting these two vectors into… Read More How does one convert a vector of variable names into a formula in R while allowing the user to specify some as factors?

Advertisements I am trying to learn vectors; it uses confusing a ranged loop. I Don’t understand how const int& i works in tandem with the single colon ‘:’ and vector1. for (const int& i : vector1) { cout << i << " "; } >Solution : As of C++11, this is available. It is a… Read More Why Is the single colon In C++ Vector call, what's its function

Advertisements So i have this program and i want to implement an insert void function. Basically i want to insert a card into the deck. The output should be a deck of cards and the shuffled version and then insert a card and sort it again. How can i accomplish that? Deck.cpp #include "deck.h" #include… Read More Insert a card into a deck of cards

Advertisements I’m trying to generate vector from wikipediaText. But when i running my def generateVector i have an error message like: list indices must be integers or slices, not str on line word2idx[word] = idx. I’ll be very thankful if somebody help me with my task. Here my code: def getVocab(inputString): inputString = inputString.lower() inputString… Read More trying to generate a vector