dump

takewhile/Makefile

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+TARGET = takewhile.elf
+SRCS = takewhile.cc
+
+all: $(TARGET)
+
+include ../config.mk

takewhile/takewhile.cc

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+#include <cassert>
+#include <iostream>
+#include <iterator>
+#include <vector>
+
+template <typename InputIt, typename OutputIt, typename Pred>
+std::pair<InputIt, OutputIt> copy_while(InputIt first, InputIt last,
+                                        OutputIt out, Pred p) {
+    // Iterate through the input range
+    while (first != last && p(*first)) {
+        *out = *first; // Copy the value to the output
+        ++first;       // Move to the next input element
+        ++out;         // Move to the next output element
+    }
+    // Return the pair of iterators
+    return {first, out};
+}
+
+std::vector<int> take_while_sum_less_than(std::vector<int> &invec, int n) {
+    std::vector<int> out;
+    int sum = 0;
+    copy_while(invec.begin(), invec.end(), std::back_inserter(out),
+               [&](int &x) -> bool { return (sum += x) < n; });
+    return out;
+}
+
+int main() {
+    // Sample data
+    std::vector<int> input = {1, 2, 3, 6,
+                              7, 8}; // We will stop copying when we encounter 6
+    std::vector<int> output;
+
+    // Define the predicate: copy while the value is <= 5
+    auto pred = [](int n) { return n <= 5; };
+
+    // Call copy_while with the test data
+    auto [new_first, new_out] = copy_while(input.begin(), input.end(),
+                                           std::back_inserter(output), pred);
+
+    // Assert that the copied elements are correct (only the first three
+    // elements)
+    std::vector<int> test = std::vector<int>{1, 2, 3};
+    assert(output == test);
+
+    // Assert that the iterator returned points to the element that did not
+    // match the predicate (6)
+    assert(*new_first == 6);
+
+    std::vector<int> v{1, 2, 3};
+    auto w = take_while_sum_less_than(v, 10);
+    std::cout << "Hello" << std::endl;
+    std::for_each(w.begin(), w.end(),
+                  [](int &a) { std::cout << a << " " << std::endl; });
+}