Google online test exercise 2

Problem

Given a list of space separated words, reverse the order of the words. Each line of text containsLLetters andWWords. A line will only consist of letters and space characters. There will be exactly one space character between each pair of consecutive words.

Input

The first line of input gives the number of cases,N.
NTest Cases Follow. For each test case there will a line of letters and space characters indicating a list of space separated words. spaces will not appear at the start or end of a line.

Output

For each test case, output one line containing "case #X: "Followed by the list of words in reverse order.

Limits

Small Dataset

N= 5
1 ≤L≤ 25

Large Dataset

N= 100
1 ≤L≤ 1000

Idea: first, one word is reversed, and then the entire string is reversed.

#include<iostream>#include<fstream>#include<string>using namespace std;int main(){int n_case;ifstream ifile("B-large-practice.in");ofstream ofile("resultb2.txt");ifile >> n_case;for(int i = 0; i <= n_case; i++){char line[1002];ifile.getline(line, 1002);string words(line);int begin = 0;int end = 0;if(i == 0)continue;for(int i = 1; i < words.length(); i++){if(words[i] ==  ' '){int sum = begin + i - 1;for(int j = begin; j <= sum / 2; j++){char tmp = words[j];words[j] = words[sum - j];words[sum - j] = tmp;}begin = i + 1;}}int sum = begin + words.length() - 1;for(int j = begin; j <= sum / 2; j++){char tmp = words[j];words[j] = words[sum - j];words[sum - j] = tmp;}sum = words.length() - 1;for(int j = 0; j <= sum / 2; j++){char tmp = words[j];words[j] = words[sum - j];words[sum - j] = tmp;}ofile << "Case #" << i << ": " << words << endl;}return 0;}

Google online test exercise 2