C++の練習を兼ねて, AtCoder Regular Contest 149 の 問題A (Repdigit Number) ~ 問題B (Two LIS Sum) を解いてみた.
■感想.
1. 問題A, Bは, 方針が見えなかったため, 解説を参考に, AC版に到達できた.
2. 問題B で, LIS(Longest increase subsequence) の 復習ができたので, 非常に良かったと思う.
3. 引き続き, 時間を見つけて, 過去問の学習を進めていきたいと思う.
本家のサイト AtCoder Regular Contest 149 解説 の 各リンク を ご覧下さい.
■C++版プログラム(問題A/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 |
// 解き直し. // https://atcoder.jp/contests/arc149/editorial/4869 // C++(GCC 9.2.1) #include <bits/stdc++.h> using namespace std; using LL = long long; #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--) int main(){ // 1. 入力情報. int N, M; scanf("%d %d", &N, &M); // 2. 正整数 X は? int n = 0, d = 0; LL X = 0; repx(i, 1, 10){ // 各桁が, i のみで構成される場合. X = i; repx(j, 1, N + 1){ // 正整数 X の 最大値候補 となるか? if(X % M == 0 && n <= j){ n = j; d = i; } // 次へ. X = (10 * X + i) % M; } } // 3. 例外. if(!n && !d){ puts("-1"); return 0; } // 4. 出力. rep(i, n) printf("%d", d); puts(""); 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 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 |
[入力例] 7 12 [出力例] 888888 ※AtCoderのテストケースより [入力例] 9 12 [出力例] 888888888 ※AtCoderのテストケースより [入力例] 1 3 [出力例] 9 ※AtCoderのテストケースより [入力例] 1000 25 [出力例] -1 ※AtCoderのテストケースより [入力例] 30 1 [出力例] 999999999999999999999999999999 ※AtCoderのテストケースより [入力例] 20 22 [出力例] 88888888888888888888 [入力例] 314 159 [出力例] 999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 [入力例] 2022 1006 [出力例] 8888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888 |
■C++版プログラム(問題B/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 |
// 解き直し. // https://atcoder.jp/contests/arc149/editorial/4910 // C++(GCC 9.2.1) #include <bits/stdc++.h> using namespace std; using vi = vector<int>; using P = pair<int, int>; using vp = vector<P>; #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 #define a first #define b second #define all(x) x.begin(), x.end() int main(){ // 1. 入力情報. int N; scanf("%d", &N); vp v(N); rep(i, N) scanf("%d", &v[i].a); rep(i, N) scanf("%d", &v[i].b); // 2. sort. sort(all(v)); // 3. 狭義単調増加な数列の長さの最大値は? // 以下の問題を参照. // https://atcoder.jp/contests/typical90/tasks/typical90_bh // -> LIS(Longest increase subsequence) を 利用. vi dp; for(auto &p : v){ if(dp.size() == 0 || dp.back() < p.b){ dp.pb(p.b); continue; } int at = lower_bound(all(dp), p.b) - dp.begin(); dp[at] = p.b; } // 4. 出力. printf("%d\n", N + dp.size()); 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 38 39 40 41 |
[入力例] 5 5 2 1 4 3 3 1 2 5 4 [出力例] 8 ※AtCoderのテストケースより [入力例] 5 1 2 3 4 5 1 2 3 4 5 [出力例] 10 ※AtCoderのテストケースより [入力例] 15 10 5 4 13 2 14 12 3 15 11 6 7 1 8 9 13 1 8 5 7 14 2 3 9 11 12 6 10 15 4 [出力例] 20 [入力例] 50 15 25 29 44 9 38 1 12 26 43 14 34 36 17 5 28 24 39 47 22 30 10 37 7 27 8 3 18 21 20 32 6 16 19 40 23 2 42 35 4 49 13 33 41 50 31 45 11 46 48 34 46 36 29 3 42 2 9 16 18 33 7 20 8 37 30 48 12 45 44 39 43 25 28 26 19 31 15 22 24 17 38 49 11 13 14 32 6 1 21 50 4 27 5 23 41 35 40 47 10 [出力例] 65 [入力例] 100 27 77 10 88 63 95 49 22 17 8 26 100 60 79 92 59 96 25 67 93 97 20 70 61 68 38 89 94 45 9 46 65 85 48 2 36 90 24 32 39 34 86 12 29 81 98 71 40 44 5 30 13 64 87 83 55 15 28 78 33 76 80 6 14 21 72 3 37 82 84 50 73 58 56 1 66 51 91 4 31 53 75 18 41 54 62 57 52 35 16 69 7 47 99 11 74 23 42 43 19 29 69 16 36 64 97 30 13 55 91 83 100 6 74 92 76 38 17 58 60 95 86 99 87 20 28 85 7 46 57 26 62 89 78 71 23 34 75 12 31 47 59 70 65 43 24 27 53 40 54 3 48 14 81 21 42 4 15 39 32 45 18 51 33 9 44 19 49 25 73 67 88 66 35 72 80 94 5 98 61 68 84 82 90 10 77 41 63 50 2 56 22 96 8 1 79 93 11 37 52 [出力例] 121 |
■参照サイト
AtCoder Regular Contest 149