C++の練習を兼ねて, AtCoder Beginner Contest 051 の 問題C (C – Back and Forth) を解いてみた.
■感想.
1. 個人的には, 非常に面白い問題と感じた.
2. 時間を見つけて, 引き続き, 過去問を振り返っていきたいと思う.
本家のサイトABC 051 解説をご覧下さい.
■C++版プログラム(問題C／AC版).
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 |
#include <bits/stdc++.h> using namespace std; #define repex(i, a, b, c) for(int i = a; i < b; i += c) #define repx(i, a, b) repex(i, a, b, 1) #define rep(i, n) repx(i, 0, n) #define repr(i, a, b) for(int i = a; i >= b; i--) #define pb push_back int main(){ // 1. 入力情報. int sx, sy, tx, ty; scanf("%d %d %d %d", &sx, &sy, &tx, &ty); // 2. イルカの最短経路を一つ求める. // 2-1. 右方向: (tx - sx)回 string ans = ""; rep(i, tx - sx) ans.pb('R'); // 2-2. 上方向: (ty - sy)回 rep(i, ty - sy) ans.pb('U'); // 2-3. 左方向: (tx - sx)回 rep(i, tx - sx) ans.pb('L'); // 2-4. 下方向: (ty - sy)回 rep(i, ty - sy) ans.pb('D'); // 2-5. 下方向: 1回 ans.pb('D'); // 2-6. 右方向: (tx - sx + 1)回 rep(i, tx - sx + 1) ans.pb('R'); // 2-7. 上方向: (ty - sy + 1)回 rep(i, ty - sy + 1) ans.pb('U'); // 2-8. 左方向: 1回 ans.pb('L'); // 2-8. 上方向: 1回 ans.pb('U'); // 2-9. 左方向: (tx - sx + 1)回 rep(i, tx - sx + 1) ans.pb('L'); // 2-10.下方向: (ty - sy + 1)回 rep(i, ty - sy + 1) ans.pb('D'); // 2-11.右方向: 1回 ans.pb('R'); // 3. 出力. printf("%s\n", ans.c_str()); return 0; } |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 |
[入力例] 0 0 1 2 [出力例] UURDDLLUUURRDRDDDLLU ※AtCoderテストケースより ※上記のプログラムだと以下のように出力される. RUULDDDRRUUULULLDDDR [入力例] -2 -2 1 1 [出力例] UURRURRDDDLLDLLULUUURRURRDDDLLDL ※AtCoderテストケースより ※上記のプログラムだと以下のように出力される. RRRUUULLLDDDDRRRRUUUULULLLLDDDDR [入力例] 0 0 1 1 [出力例] RULDDRRUULULLDDR [入力例] 11 19 31 47 [出力例] RRRRRRRRRRRRRRRRRRRRUUUUUUUUUUUUUUUUUUUUUUUUUUUULLLLLLLLLLLLLLLLLLLLDDDDDDDDDDDDDDDDDDDDDDDDDDDDDRRRRRRRRRRRRRRRRRRRRRUUUUUUUUUUUUUUUUUUUUUUUUUUUUULULLLLLLLLLLLLLLLLLLLLLDDDDDDDDDDDDDDDDDDDDDDDDDDDDDR [入力例] 3 14 15 92 [出力例] RRRRRRRRRRRRUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUULLLLLLLLLLLLDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDRRRRRRRRRRRRRUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUULULLLLLLLLLLLLLDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDR |
■参照サイト
AtCoder Beginner Contest 051