枚举推式子
1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long LL; 4 LL gcd(LL a, LL b){ 5 return a % b ? gcd(b, a % b) : b; 6 } 7 int main(){ 8 int T; 9 scanf("%d", &T); 10 while(T--) { 11 LL K, M, six = 6; 12 cin >> K >> M; 13 LL a = K + 1, b = K + 2, c = K + 3; 14 LL g = gcd(a, six); 15 a /= g, six /= g; 16 g = gcd(b, six); 17 b /= g, six /= g; 18 g = gcd(c, six); 19 c /= g, six /= g; 20 LL ans = a * b % M * c % M; 21 cout << ans << endl; 22 } 23 return 0; 24 }
子树修改子树询问转路径标记
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn = 1e6 + 10; 4 typedef long long LL; 5 6 int node; 7 LL val[maxn], num[maxn], del[maxn]; 8 LL sum[maxn], tot[maxn]; 9 map<char, int> G[maxn]; 10 void insert(string s, LL v){ 11 int p = 0; 12 for(int i = 0; i < s.length(); ++i){ 13 if(G[p].find(s[i]) == G[p].end()) G[p][s[i]] = ++node; 14 p = G[p][s[i]]; 15 v -= del[p]; 16 sum[p] += v; 17 tot[p]++; 18 } 19 val[p] += v; 20 num[p]++; 21 } 22 void modify(string s, LL v) { 23 int p = 0; 24 for (int i = 0; i < s.length(); ++i) { 25 if (G[p].find(s[i]) == G[p].end()) G[p][s[i]] = ++node; 26 p = G[p][s[i]]; 27 } 28 del[p] += v; 29 LL tmp = tot[p]; 30 p = 0; 31 for (int i = 0; i < s.length(); ++i) { 32 if (G[p].find(s[i]) == G[p].end()) G[p][s[i]] = ++node; 33 p = G[p][s[i]]; 34 if(i != s.length() - 1) sum[p] += tmp * v; 35 } 36 } 37 LL Q1(string s) { 38 int p = 0; 39 LL tmp = 0; 40 for (int i = 0; i < s.length(); ++i) { 41 if (G[p].find(s[i]) == G[p].end()) G[p][s[i]] = ++node; 42 p = G[p][s[i]]; 43 tmp += del[p]; 44 } 45 return val[p] + tmp * num[p]; 46 } 47 LL Q2(string s) { 48 int p = 0; 49 LL tmp = 0; 50 for (int i = 0; i < s.length(); ++i) { 51 if (G[p].find(s[i]) == G[p].end()) G[p][s[i]] = ++node; 52 p = G[p][s[i]]; 53 tmp += del[p]; 54 } 55 return sum[p] + tmp * tot[p]; 56 } 57 58 char s[maxn]; 59 int main(){ 60 int N; 61 scanf("%d", &N); 62 for(int i = 1; i <= N; ++i){ 63 int o, a, b; 64 scanf("%d", &o); 65 if(o == 1){ 66 scanf("%s %d", s, &a); 67 insert(string(s), a); 68 } 69 else if(o == 2){ 70 scanf("%s %d", s, &a); 71 modify(string(s), a); 72 } 73 else if(o == 3){ 74 scanf("%s", s); 75 printf("%lld ", Q1(string(s))); 76 } 77 else{ 78 scanf("%s", s); 79 printf("%lld ", Q2(string(s))); 80 } 81 } 82 return 0; 83 }
缩点
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn = 1e5 + 10; 4 5 // BCC 6 set<int> SE[maxn], ans; 7 set<int> :: iterator it; 8 stack<int> S; 9 vector<int> G[maxn]; 10 int dfs_clock, dfn[maxn], low[maxn]; 11 int bcc_cnt, bccno[maxn]; 12 void dfs(int u, int fa) 13 { 14 dfn[u] = low[u] = ++dfs_clock; 15 S.push(u); 16 for(int i = 0; i < G[u].size(); ++i) 17 { 18 int v = G[u][i]; 19 if(!dfn[v]) 20 { 21 dfs(v, u); 22 low[u] = min(low[u], low[v]); 23 } 24 else if(!bccno[v]) low[u] = min(low[u], dfn[v]); 25 } 26 27 if(low[u] == dfn[u]) 28 { 29 bcc_cnt++; 30 while(1) 31 { 32 int x = S.top(); S.pop(); 33 bccno[x] = bcc_cnt; 34 SE[bcc_cnt].insert(x); 35 if(x == u) break; 36 } 37 } 38 } 39 40 void find_bcc(int n) 41 { 42 memset(dfn, 0, sizeof(dfn)); 43 memset(bccno, 0, sizeof(bccno)); 44 dfs_clock = bcc_cnt = 0; 45 for(int i = 1; i <= n; i++) if(!dfn[i]) dfs(i, 0); 46 } 47 48 int deg[maxn]; 49 int main(){ 50 int n, m; 51 scanf("%d %d", &n, &m); 52 for(int i = 1; i <= m; ++i){ 53 int u, v; 54 scanf("%d %d", &u, &v); 55 G[u].push_back(v); 56 } 57 find_bcc(n); 58 for(int i = 1; i <= n; ++i){ 59 for(int j = 0; j < G[i].size(); ++j) 60 if(bccno[i] != bccno[G[i][j]]) deg[bccno[G[i][j]]]++; 61 } 62 for(int i = 1; i <= bcc_cnt; ++i){ 63 if(deg[i] == 0) ans.insert(*SE[i].begin()); 64 } 65 printf("%d ", ans.size()); 66 for(it = ans.begin(); it != ans.end(); it++){ 67 if(it != ans.begin()) putchar(' '); 68 printf("%d", *it); 69 } 70 puts(""); 71 return 0; 72 }
启发式合并
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn = 1e5 + 10; 4 typedef long long LL; 5 typedef pair<int, int> pii; 6 vector<pii> G[maxn]; 7 int n, m; 8 9 int sz[maxn]; 10 LL bt[maxn]; 11 void dfs(int x, int f){ 12 bt[x] = 0; 13 sz[x] = 1; 14 for(int i = 0; i < G[x].size(); ++i){ 15 int to = G[x][i].first, d = G[x][i].second; 16 if(to == f) continue; 17 dfs(to, x); 18 bt[x] += bt[to] + d * sz[to]; 19 sz[x] += sz[to]; 20 } 21 } 22 23 LL ans; 24 int id[maxn]; 25 map<LL, int> S[maxn]; 26 map<LL, int> :: iterator it; 27 void add(int x, int f, int y){ 28 S[y][bt[x]] = 1; 29 for(int i = 0; i < G[x].size(); ++i){ 30 int to = G[x][i].first; 31 if(to == f) continue; 32 add(to, x, y); 33 } 34 } 35 void dfs1(int x, int f){ 36 id[x] = x; 37 int M = 0, ms = 0; 38 for(int i = 0; i < G[x].size(); ++i){ 39 int to = G[x][i].first; 40 if(to == f) continue; 41 dfs1(to, x); 42 if(sz[to] > M) M = sz[to], ms = to; 43 } 44 if(ms) id[x] = id[ms]; 45 for(int i = 0; i < G[x].size(); ++i){ 46 int to = G[x][i].first; 47 if(to == f || to == ms) continue; 48 add(to, x, id[x]); 49 } 50 it = S[id[x]].lower_bound(bt[x] - m); 51 if(it != S[id[x]].end()) ans = max(ans, bt[x] - (*it).first); 52 S[id[x]][bt[x]] = 1; 53 } 54 55 int main(){ 56 int T; 57 scanf("%d", &T); 58 while(T--){ 59 scanf("%d %d", &n, &m); 60 for(int i = 1; i <= n; ++i) G[i].clear(), S[i].clear(); 61 for(int i = 1; i < n; ++i){ 62 int u, v, d; 63 scanf("%d %d %d", &u, &v, &d); 64 G[u].push_back(pii(v, d)); 65 G[v].push_back(pii(u, d)); 66 } 67 ans = -1; 68 dfs(1, 0); 69 dfs1(1, 0); 70 printf("%lld ", ans); 71 } 72 return 0; 73 }
倒着并茶几
1 #include <bits/stdc++.h> 2 using namespace std; 3 const int maxn = 1e5 + 10; 4 int a[maxn], b[maxn], ans[maxn]; 5 int base[maxn][33], vis[maxn]; 6 7 int fa[maxn]; 8 int Find(int x){ 9 return fa[x] == x ? x : fa[x] = Find(fa[x]); 10 } 11 void Union(int x, int y){ 12 x = Find(x), y = Find(y); 13 if(x == y) return; 14 for(int i = 29; i >= 0; i--){ 15 if(!base[x][i]) continue; 16 for(int j = 29; j >= 0; j--){ 17 if((1 << j) & base[x][i]){ 18 if(base[y][j]) base[x][i] ^= base[y][j]; 19 else { 20 base[y][j] = base[x][i]; 21 break; 22 } 23 } 24 } 25 } 26 fa[x] = y; 27 } 28 29 int main(){ 30 int N, M = 0; 31 scanf("%d", &N); 32 for(int i = 1; i <= N; ++i) fa[i] = i; 33 for(int i = 1; i <= N; ++i) scanf("%d", a + i); 34 for(int i = 1; i <= N; ++i) scanf("%d", b + i); 35 for(int i = N; i >= 1; --i){ 36 int x = a[b[i]], y = 0; 37 for(int j = 29; j >= 0; --j){ 38 if((1 << j) & x){ 39 base[b[i]][j] = x; 40 break; 41 } 42 } 43 vis[b[i]] = 1; 44 if(vis[b[i] - 1]) Union(b[i] - 1, b[i]); 45 if(vis[b[i] + 1]) Union(b[i] + 1, b[i]); 46 x = Find(b[i]); 47 for(int j = 29; j >= 0; --j){ 48 if((1 << j) & y) continue; 49 y ^= base[x][j]; 50 } 51 M = max(M, y); 52 ans[i] = M; 53 } 54 for(int i = 1; i <= N; ++i) printf("%d ", ans[i]); 55 return 0; 56 }