iFLYTEK Written Exam Questions Review

Question 1: Given a string with some words separated by an indeterminate number of spaces, count the number of words containing the character e;

This is relatively simple and will not be solved;

The second question, given four points, calculate the corresponding convex quadrilateral area, the point is the given structure;

I didn't write it down: I can't make this basic test math formula if I don't know it, and it has no reference value, so I won't review it;

The third question, given a string, find the number of iflytek in the subsequence of the string

This is also not written, g, the backtracking template is not written correctly!!!

backtracking(str, i + 1); not backtracking(startIndex + 1);

Violent backtracking:

#include using namespace std;string target = "iflytek";string path;int res = 0;bool isPath(string& path) {for (int i = 0; i < path. size(); ++i) {if (path[i] != target[i]) return false;}return true;}void backtracking(const string& str, int startIndex) {if (!isPath(path)) return;if (path == target) {res++;return;}for (int i = startIndex; i < str.size(); ++i) {path.push_back(str[i]);backtracking(str, i + 1);path.pop_back();}}int findiflytek(string& str) {backtracking(str, 0);return res;}int main() {string str = "iflytekiflytek";cout << findiflytek(str) << endl;return 0;}

Dynamic programming solution: to see!