Problem A: New Year Candles (379A)
题目大意:给出a和b,表示有现在有a根蜡烛,烧完b根蜡烛后可以换取新的一根蜡烛,问最多可以点多少根蜡烛。
解题思路:水题。
#include <stdio.h> #include <string.h> int main() { int ans = 0, a, b; scanf("%d%d", &a, &b); while (a >= b) { ans += (a / b) * b; a = a / b + a % b; } printf("%d\n", ans + a); return 0; }
Problem B: New Year Present (379B)
题目大意:机器人为桌子上的钱包塞硬币,给出每个钱包需要放多少个硬币,然后机器人从最左边开始放硬币,不能连续放两次硬币,输出机器人的操纵。
解题思路:因为不需要说最少步数,所以每个位置放一次礼物后就移动到旁边再移动回来就可以了,注意最左边的只能往右移动。
#include <stdio.h> #include <string.h> const int N = 305; int n, c[N]; int main() { scanf("%d", &n); for (int i = 0; i < n; i++) scanf("%d", &c[i]); for (int i = 0; i < c[0]; i++) printf("PRL"); for (int i = 1; i < n; i++) { printf("R"); for (int j = 0; j < c[i]; j++) printf("PLR"); } printf("\n"); return 0; }
Problem C:New Year Ratings Change(379C)
题目大意:有n个人,每个人在新年有想要礼物的个数,你需要满足所有人的需求,即礼物个数大于等于他想要的个数,并且送给每个人的礼物数不能相同。
解题思路:将需求从小到大排序,然后维持一个最小礼物数即可。
#include <stdio.h> #include <string.h> #include <algorithm> using namespace std; const int N = 300005; struct state { int x, id; }s[N]; int n, c[N]; bool cmp(const state& a, const state& b) { return a.x < b.x; } int main() { scanf("%d", &n); for (int i = 0; i < n; i++) { scanf("%d", &s[i].x); s[i].id = i; } sort(s, s + n, cmp); int tmp = 0; for (int i = 0; i < n; i++) { c[s[i].id] = max(s[i].x, tmp); tmp = c[s[i].id] + 1; } printf("%d", c[0]); for (int i = 1; i < n; i++) printf(" %d", c[i]); printf("\n"); return 0; }
Problem D:New Year Letter(379D)
题目大意:给出k,x,n,m。现在有字符串s1,s2长度分别为n和m。si = si-2 + si-1。问说能否找出sk中正好含有x个"AC"。
解题思路:要注意s1=A,s2=C,那么s3=AC这样一类情况。原先是ci=ci-2+ci-1,但是出现刚才的情况就会变成ci=ci-2+ci-1 + 1。所以要枚举s1和s2的头尾,以及AC个数。
#include <stdio.h> #include <iostream> using namespace std; typedef long long ll; const char sign[3] = {'A', 'B', 'C' }; int k, n, m; ll x; int count(int c, int pre, int end) { if (pre != 0) c--; if (end != 2) c--; return c / 2; } bool judge(ll p, ll q, char fpre, char fend, char spre, char send) { for (int i = 3; i <= k; i++) { ll t = p + q; char ch = fpre; if (fend == 'A' && spre == 'C') t++; p = q; fpre = spre; fend = send; q = t; spre = ch; } return q == x; } void put(int c, int s, int pre, int end) { printf("%c", sign[pre]); if (s == 1) return; s--; if (c && pre == 0) { printf("C"); c--; s--; } for (int i = 0; i < c; i++) printf("AC"); s -= 2 * c; for (int i = 1; i < s; i++) printf("B"); if (s) printf("%c", sign[end]); } bool solve() { for (int fpre = 0; fpre < 3; fpre++) { for (int fend = 0; fend < 3; fend++) { if (n == 1 && fpre != fend) continue; for (int spre = 0; spre < 3; spre++) { for (int send = 0; send < 3; send++) { if (m == 1 && spre != send) continue; int p = count(n, fpre, fend), q = count(m, spre, send); for (int i = 0; i <= p; i++) { for (int j = 0; j <= q; j++) { if (judge(i, j, sign[fpre], sign[fend], sign[spre], sign[send])) { put(i, n, fpre, fend); printf("\n"); put(j, m, spre, send); printf("\n"); return true; } } } } } } } return false; } int main() { scanf("%d", &k); cin >> x; scanf("%d%d", &n, &m); if (!solve()) printf("Happy new year!\n"); return 0; }