一、CodeJam T恤
CodeJam(又称谷歌编程大赛)是谷歌公司举办的一项全球性编程比赛,旨在为全球程序员提供一个交流平台和提高自己编程能力的机会。每年谷歌都会派发一些活动纪念品来丰富比赛参与者的收藏,其中最受欢迎的莫过于CodeJam T恤。这种T恤的设计很特别,上面包含着历届CodeJam的logo或者CodeJam比赛的难题名称,很适合那些富有纪念意义的程序员们收藏。
CodeJam T-Shirt: #include <iostream> #include <string> using namespace std; int main() { string tShirt; getline(cin, tShirt); cout << "I love my CodeJam T-shirt with " << tShirt << " printed on it!" << endl; return 0; }
二、CodeJam是什么比赛
CodeJam是一种面向全球程序员的编程比赛,更确切地说,CodeJam是一种算法竞赛。CodeJam比赛不需注册费用,全程使用英语,官方旨在推广计算机科学和编程,鼓励优秀的问题解决能力及创新精神,并吸引人才加入Google。
#include <iostream> #include <cmath> using namespace std; int main() { int testCases; cin >> testCases; for (int i = 1; i <= testCases; i++) { double a, b, c; cin >> a >> b >> c; double s = (a + b + c) / 2; double area = sqrt(s*(s-a)*(s-b)*(s-c)); cout << "Case #" << i << ": " << area << endl; } return 0; }
三、CodeJam难度
CodeJam比赛的难度层级比较高,涉及到算法、数据结构、编程的全方面技能。难度从Round 1(R1)到Finals,依次递增,同时每个Round附带着若干题目,参赛选手需要根据难度选择自己最为擅长的部分加以解决,操作难度和解题难度都需要一定的技巧。
#include <iostream> #include <string> using namespace std; int main() { int n; cin >> n; string s; getline(cin, s); for (int i = 0; i < n; i++) { getline(cin, s); int length = s.length(); int j = 0; bool hasPlusSign = false; while (j < length) { if (s[j] == '+') { hasPlusSign = true; break; } j++; } if (hasPlusSign) { int result = 0; int k; for (k = 0; k < j; k++) { if (s[k] != ' ') { result += (s[k] - '0'); result *= 10; } } result /= 10; cout << "Case #" << (i + 1) << ": " << result << endl; } else { cout << "Case #" << (i + 1) << ": " << j << endl; } } return 0; }
四、CodeJam题目
CodeJam比赛的难题覆盖了众多计算机领域,并且难度层次比较严谨。通常情况下,难度递增的题目分为Round 1 (R1)、Round 2 (R2)、Round 3 (R3)、Online Qualification Round等等。以下是一道CodeJam R1B的例题:A.
#include <iostream> #include <string> #include <vector> using namespace std; int main() { int t, n; string s; cin >> t; for (int i = 1; i <= t; i++) { cin >> n >> s; vectorgroups; int currGroup = 1; for (int j = 1; j < s.size(); j++) { if (s[j] == s[j - 1]) { currGroup++; } else { groups.push_back(currGroup); currGroup = 1; } } groups.push_back(currGroup); int ans = 0; for (int j = 1; j < groups.size(); ++j) { ans += min(groups[j], groups[j - 1]); } cout << "Case #" << i << ": " << ans << endl; } return 0; }
五、CodeJam 2022
CodeJam每年都会举办比赛,2022年度CodeJam也不例外。根据官网的消息,2022年度的CodeJam已经与2021年一样,分 R1A、R1B、R2、R3 四个轮次。诚邀各位优秀的程序员们踊跃参加,一起切磋编程技艺!
#include <iostream> #include <cstdlib> using namespace std; int main() { cout << "Welcome to CodeJam 2022!" << endl; srand(2022); int a = rand() % 100; int b = rand() % 100; cout << "Let's do some math: " << a << " + " << b << " = ?" << endl; int answer; cin >> answer; if (answer == a + b) { cout << "Congratulations, you got the right answer!" << endl; } else { cout << "Sorry, the correct answer is " << a + b << endl; } return 0; }
六、CodeJam Round 2
CodeJam 的Round 2比赛难度要更高,但是也能在很多领域为程序员们提供更多的挑战。以下是一道CodeJam 2020 Round 2的例题:B。
#include <iostream> #include <algorithm> #include <vector> #include <cstring> using namespace std; const int MAXN = 1e5 + 10; long long ans[MAXN], score[MAXN]; struct Q { int l, r, id; Q() {}; Q(int l_, int r_, int id_) {l = l_; r = r_; id = id_;} bool operator < (const Q &other) const { if (l / 320 != other.l / 320) { return l / 320 < other.l / 320; } return r < other.r; } }; vectorg[MAXN]; int a[MAXN], start[MAXN], end[MAXN]; bool seen[MAXN]; int t, n, q, cnt, b[MAXN], c[MAXN]; long long dfs(int u, int p) { seen[u] = true; start[u] = cnt; b[cnt] = a[u]; c[cnt] = u; cnt++; for (int v : g[u]) { if (v != p) { dfs(v, u); b[cnt] = a[u]; c[cnt] = u; cnt++; } } end[u] = cnt; return score[u]; } int main() { cin >> t; for (int qq = 1; qq <= t; qq++) { cin >> n >> q; memset(seen, false, sizeof(seen)); for (int i = 1; i <= n; i++) { g[i].clear(); cin >> a[i]; } for (int i = 1; i <= n; i++) { cin >> score[i]; } for (int i = 1; i <= n - 1; i++) { int x, y; cin >> x >> y; g[x].push_back(y); g[y].push_back(x); } dfs(1, -1); vector queries; for (int i = 1; i <= q; i++) { int l, r; cin >> l >> r; queries.push_back(Q(l, r, i)); } sort(queries.begin(), queries.end()); int st = 0, ed = 0; long long sum = 0; for (Q x : queries) { int l = x.l, r = x.r, id = x.id; while (ed < r) { sum += score[c[ed]] - b[ed]; ed++; } while (st > l) { sum += score[c[st-1]] - b[st-1]; st--; } while (st < l) { sum -= score[c[st]] - b[st]; st++; } while (ed > r) { sum -= score[c[ed-1]] - b[ed-1]; ed--; } ans[id] = sum; } cout << "Case #" << qq << ": "; for (int i = 1; i <= q; i++) { cout << ans[i]; if (i != q) { cout << " "; } } cout << endl; } return 0; }