题目链接
SB 裸题……就是想随便挂在这里……同样的题还有 Luogu_2014 选课。
Luogu_2015 二叉苹果树
1 #include <queue> 2 #include <cstdio> 3 #include <cctype> 4 #include <cstring> 5 #include <iostream> 6 #include <algorithm> 7 using namespace std; 8 9 const int maxn = 100 + 10; 10 int n, m, head[maxn], size[maxn], val[maxn], dp[maxn][maxn],ans, edge_num; 11 12 struct Edge { int v, w, nxt; } edge[maxn << 1]; 13 14 inline int read() { 15 register char ch = 0; register int w = 0, x = 0; 16 while( !isdigit(ch) ) w |= (ch == '-'), ch = getchar(); 17 while( isdigit(ch) ) x = (x * 10) + (ch ^ 48), ch = getchar(); 18 return w ? -x : x; 19 } 20 21 inline void Add_edge(int u, int v, int w) { 22 edge[++edge_num].v = v, edge[edge_num].w = w; 23 edge[edge_num].nxt = head[u], head[u] = edge_num; 24 } 25 26 inline int Set_value(int x, int p) { 27 for(int i = head[x]; i; i = edge[i].nxt) { 28 if( edge[i].v == p ) continue; 29 size[x] = size[x] + Set_value(edge[i].v, x), val[edge[i].v] = edge[i].w; 30 } 31 return ++size[x]; 32 } 33 34 inline void Deep_fs(int x, int p) { 35 vector<pair<int, int> > v; 36 for(int i = head[x]; i; i = edge[i].nxt) { 37 if( edge[i].v == p ) continue; 38 v.clear(), Deep_fs(edge[i].v, x); 39 for(int j = 0; j <= min(size[edge[i].v], m); ++j) 40 v.push_back(make_pair(j + 1, dp[edge[i].v][j] + val[edge[i].v])); 41 for(int j = m; j > 0; --j) 42 for(int k = 0; k < v.size(); ++k) 43 if( j >= v[k].first ) dp[x][j] = max(dp[x][j], dp[x][j - v[k].first] + v[k].second); 44 } 45 } 46 47 int main(int argc, const char *argv[]) 48 { 49 freopen("..\nanjolno.in", "r", stdin); 50 freopen("..\nanjolno.out", "w", stdout); 51 52 scanf("%d%d", &n, &m); 53 for(int u, v, w, i = 1; i < n; ++i) 54 u = read(), v = read(), w = read(), Add_edge(u, v, w), Add_edge(v, u, w); 55 Set_value(1, 0), Deep_fs(1, 0), printf("%d ", dp[1][m]); 56 57 fclose(stdin), fclose(stdout); 58 return 0; 59 }
Luogu_2014 选课
1 #include <queue> 2 #include <cstdio> 3 #include <cctype> 4 #include <cstring> 5 #include <iostream> 6 #include <algorithm> 7 using namespace std; 8 9 const int maxn = 300 + 10; 10 int n, m, head[maxn], val[maxn], siz[maxn], dp[maxn][maxn], edge_num; 11 12 struct Edge { int v, nxt; } edge[maxn]; 13 14 inline int read() { 15 register char ch = 0; register int w = 0, x = 0; 16 while( !isdigit(ch) ) w |= (ch == '-'), ch = getchar(); 17 while( isdigit(ch) ) x = (x * 10) + (ch ^ 48), ch = getchar(); 18 return w ? -x : x; 19 } 20 21 inline void Add_edge(int u, int v) { 22 edge[++edge_num].v = v; 23 edge[edge_num].nxt = head[u], head[u] = edge_num; 24 } 25 26 inline int Deep_fs(int x, int p) { 27 for(int i = head[x]; i; i = edge[i].nxt) { 28 if( edge[i].v == p ) continue; 29 siz[x] = siz[x] + Deep_fs(edge[i].v, x); 30 for(int j = m; j >= 0; --j) 31 for(int k = 0; k <= min(m, siz[edge[i].v]); ++k) 32 if( j >= k + 1 ) dp[x][j] = max(dp[x][j], dp[x][j - k - 1] + dp[edge[i].v][k] + val[edge[i].v]); 33 } 34 return ++siz[x]; 35 } 36 37 int main(int argc, const char *argv[]) 38 { 39 freopen("..\nanjolno.in", "r", stdin); 40 freopen("..\nanjolno.out", "w", stdout); 41 42 scanf("%d%d", &n, &m); 43 for(int v, i = 1; i <= n; ++i) v = read(), val[i] = read(), Add_edge(v, i); 44 Deep_fs(0, -1), printf("%d ", dp[0][m]); 45 46 fclose(stdin), fclose(stdout); 47 return 0; 48 }
—— 假如我今生无份遇到你，就让我永远感到恨不相逢 —— 让我念念不忘，让我在醒时梦中都怀带着这悲哀的苦痛。