70 lines
2.2 KiB
C++
70 lines
2.2 KiB
C++
#include <vector>
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#include <numeric>
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#include <algorithm>
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#include <iostream>
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class CustomFunction {
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public:
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int f(int x, int y);
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};
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/**
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* 1237. Find Positive Integer Solution for a Given Equation
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* Given a callable function f(x, y) with a hidden formula and a value z, reverse engineer the formula and return all positive integer pairs x and y where f(x,y) == z. You may return the pairs in any order.
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*
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* While the exact formula is hidden, the function is monotonically increasing, i.e.:
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*
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* f(x, y) < f(x + 1, y)
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* f(x, y) < f(x, y + 1)
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* The function interface is defined like this:
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*
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* interface CustomFunction {
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* public:
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* // Returns some positive integer f(x, y) for two positive integers x and y based on a formula.
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* int f(int x, int y);
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* };
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* We will judge your solution as follows:
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*
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* The judge has a list of 9 hidden implementations of CustomFunction, along with a way to generate an answer key of all valid pairs for a specific z.
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* The judge will receive two inputs: a function_id (to determine which implementation to test your code with), and the target z.
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* The judge will call your findSolution and compare your results with the answer key.
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* If your results match the answer key, your solution will be Accepted.
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*/
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class Solution {
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public:
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static std::vector<std::vector<int>> findSolution(CustomFunction& cf, int z) {
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std::vector<int> p(1000);
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std::iota(p.begin(), p.end(), 1);
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auto L = std::lower_bound(p.begin(), p.end(), z, [&](int x, int y) {
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return cf.f(x, 1000) < y;
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}), R = std::upper_bound(p.begin(), p.end(), z, [&](int x, int y) {
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return cf.f(y, 1) > x;
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});
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std::vector<std::vector<int>> ret;
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std::for_each(L, R, [&](int x) {
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auto L2 = std::lower_bound(p.begin(), p.end(), z, [&](int m, int n) {
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return cf.f(x, m) < n;
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}), R2 = std::upper_bound(p.begin(), p.end(), z, [&](int m, int n) {
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return cf.f(x, n) > m;
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});
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std::for_each(L2, R2, [&](int y) {
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ret.push_back({x, y});
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});
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});
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return ret;
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}
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};
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int CustomFunction::f(int x, int y) {
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return x * y;
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}
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int main() {
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CustomFunction f;
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auto ret = Solution::findSolution(f, 5);
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for (auto p : ret)
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std::cout << p[0] << ", " << p[1] << std::endl;
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return 0;
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}
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