C++ 模版整理
强连通 Tarjan
1 #include <iostream> 2 #include <cstdio> 3 #include <algorithm> 4 #define ll long long 5 struct node{ 6 ll next,v; 7 }edge[1001]; 8 const int maxn=10010; 9 ll n,m,a,b,last[1001],tot,cnt,low[maxn],dfn[maxn],index,stack[maxn]; 10 bool v[maxn]; 11 inline ll min(ll a,ll b) 12 { 13 return a<b?a:b; 14 } 15 inline void read(ll &k) 16 { 17 ll f=1;k=0;char c=getchar(); 18 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 19 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 20 k*=f; 21 } 22 void tarjan(ll now) 23 { 24 dfn[now]=low[now]=++tot; 25 stack[++index]=now; 26 v[now]=1; 27 for (int i=last[now];i;i=edge[i].next) 28 { 29 if (!dfn[edge[i].v]) 30 { 31 tarjan(edge[i].v); 32 low[now]=min(low[now],low[edge[i].v]); 33 } 34 else if (v[edge[i].v]) low[now]=min(low[now],dfn[edge[i].v]); 35 } 36 if (low[now]==dfn[now]) 37 { 38 do{ 39 printf("%lld ",stack[index]); 40 v[stack[index--]]=0; 41 }while (now!=stack[index+1]); 42 printf("\n"); 43 } 44 } 45 inline void add(ll a,ll b) 46 { 47 edge[++cnt].next=last[a]; 48 edge[cnt].v=b; 49 last[a]=cnt; 50 } 51 int main() 52 { 53 read(n);read(m); 54 for (int i=1;i<=m;i++) 55 { 56 read(a);read(b); 57 add(a,b); 58 } 59 for (int i=1;i<=n;i++) 60 if (!dfn[i])tarjan(i); 61 }
LCA Tarjan
1 #include <iostream> 2 #include <cstdio> 3 const int maxn=500000*2+100; 4 int n,m,i,to[maxn],root,x,y,last[maxn],next[maxn],next1[maxn],last1[maxn],to1[maxn],ans[maxn],fa[maxn],v[maxn]; 5 using namespace std; 6 inline void read(int &k) 7 { 8 int f=1;char c=getchar();k=0; 9 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 10 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 11 k*=f; 12 } 13 inline int gf(int now) 14 { 15 return fa[now]==now?now:fa[now]=gf(fa[now]); 16 } 17 inline void dfs(int now) 18 { 19 v[now]=1; 20 for(int cur=last[now];cur;cur=next[cur]) 21 { 22 if (!v[to[cur]]) 23 { 24 dfs(to[cur]); 25 fa[to[cur]]=now; 26 } 27 } 28 for (int cur=last1[now];cur;cur=next1[cur]) 29 if (v[to1[cur]])ans[(cur+1)>>1]=gf(to1[cur]); 30 } 31 int main() 32 { 33 read(n);read(m);read(root); 34 for (i=1;i<n;i++) 35 { 36 read(x);read(y); 37 to[i*2-1]=y; 38 next[i*2-1]=last[x]; 39 last[x]=i*2-1; 40 to[i*2]=x; 41 next[i*2]=last[y]; 42 last[y]=i*2; 43 } 44 for (i=1;i<=m;i++) 45 { 46 read(x);read(y); 47 to1[i*2-1]=y; 48 next1[i*2-1]=last1[x]; 49 last1[x]=i*2-1; 50 to1[i*2]=x; 51 next1[i*2]=last1[y]; 52 last1[y]=i*2; 53 } 54 for (i=1;i<=n;i++)fa[i]=i; 55 dfs(root); 56 for (i=1;i<=m;i++) 57 printf("%d\n",ans[i]); 58 }
线段树
1 #include <iostream> 2 #include <cstdio> 3 #include <algorithm> 4 #define ll long long 5 using namespace std; 6 ll n,m,l,r,tmp,add; 7 const int maxn=200000; 8 ll le[maxn*4],ri[maxn*4],delta[maxn*4],sum[maxn*4]; 9 void read(ll &k) 10 { 11 k=0;ll f=1;char c=getchar(); 12 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 13 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 14 k*=f; 15 } 16 void build(ll l,ll r,ll cur) 17 { 18 le[cur]=l;ri[cur]=r; 19 if (l==r){read(sum[cur]);return;} 20 build(l,(l+r)>>1,cur*2); 21 build(((l+r)>>1)+1,r,cur*2+1); 22 sum[cur]=sum[cur*2]+sum[cur*2+1]; 23 } 24 ll query(ll l,ll r,ll cur) 25 { 26 if (l<=le[cur]&&ri[cur]<=r)return sum[cur]+delta[cur]*(ri[cur]-le[cur]+1); 27 ll ret=0; 28 delta[cur*2]+=delta[cur]; 29 delta[cur*2+1]+=delta[cur]; 30 sum[cur]+=delta[cur]*(ri[cur]-le[cur]+1); 31 delta[cur]=0; 32 if (l<=(le[cur]+ri[cur])>>1)ret=query(l,r,cur*2); 33 if (r>(le[cur]+ri[cur])>>1)ret+=query(l,r,cur*2+1); 34 return ret; 35 } 36 void update(ll l,ll r,ll add,ll cur) 37 { 38 if (l<=le[cur]&&r>=ri[cur]){delta[cur]+=add;return;} 39 if (l<=(le[cur]+ri[cur])>>1)update(l,r,add,cur*2); 40 if (r>(le[cur]+ri[cur])>>1)update(l,r,add,cur*2+1); 41 sum[cur]=sum[cur*2]+delta[cur*2]*(ri[cur*2]-le[cur*2]+1); 42 sum[cur]+=sum[cur*2+1]+delta[cur*2+1]*(ri[cur*2+1]-le[cur*2+1]+1); 43 } 44 int main() 45 { 46 read(n); 47 build(1,n,1); 48 read(m); 49 for (int i=0;i<m;i++) 50 { 51 read(tmp); 52 if (tmp==1) 53 { 54 read(l);read(r);read(add); 55 update(l,r,add,1); 56 } 57 if (tmp==2) 58 { 59 read(l);read(r); 60 printf("%lld\n",query(l,r,1)); 61 } 62 } 63 }
快速幂
1 #include <iostream> 2 #include <cstdio> 3 using namespace std; 4 int a,b; 5 long long qp(int a,int b) 6 { 7 int t=1;int y=a; 8 while (b) 9 { 10 if (b&1) t=t*y;//whether odd or not 11 y=y*y; 12 b=b>>1; 13 //cout << a << " " << b << " " << t << " " << y << endl; 14 } 15 return(t); 16 } 17 int main() 18 { 19 scanf("%d %d",&a,&b); 20 printf("%lld",qp(a,b)); 21 }
Kruskal
1 #include <iostream> 2 #include <cstdio> 3 #include <algorithm> 4 #include <cstdio> 5 #define ll long long 6 using namespace std; 7 struct poi{ll x,y,cost;}p[100001]; 8 ll n,m,ans,fa[100001]; 9 bool cmp(poi a,poi b){return a.cost<b.cost;} 10 int gf(ll v){return fa[v]==v?v:fa[v]=gf(fa[v]);} 11 int main() 12 { 13 scanf("%lld %lld",&n,&m); 14 for (int i=0;i<=n;i++)fa[i]=i; 15 for (int i=0;i<m;i++)scanf("%lld %lld %lld",&p[i].x,&p[i].y,&p[i].cost); 16 sort(p,p+m,cmp); 17 for (int i=0;i<m;i++) 18 { 19 int x=gf(p[i].x),y=gf(p[i].y); 20 if (x!=y) ans+=p[i].cost,fa[x]=y; 21 } 22 printf("%lld\n",ans); 23 }
KMP
1 #include <iostream> 2 #include <cstring> 3 #include <algorithm> 4 #include <cstdio> 5 #define ll long long 6 using namespace std; 7 ll n,m,f[23333],j; 8 char p[2333],t[2333]; 9 inline void read(ll &k) 10 { 11 ll f=1;char c=getchar();k=0; 12 while (c<'0'||c>'9')c=='-'&&(f=-1),c=getchar(); 13 while (c>='0'&&c<='9')k=k*10+c-'0',c=getchar(); 14 k*=f; 15 } 16 inline void getfail() 17 { 18 f[0]=0;f[1]=0; 19 for (int i=1;i<m;i++) 20 { 21 j=f[i]; 22 while ((j>0)&&(t[i]!=t[j]))j=f[j]; 23 if (t[i]==t[j])f[i+1]=j+1;else f[i+1]=0; 24 } 25 } 26 int main() 27 { 28 scanf("%s %s",p,t); 29 n=strlen(p); 30 m=strlen(t); 31 getfail(); 32 j=0; 33 for (int i=0;i<n;i++) 34 { 35 while ((j>0)&&(p[i]!=t[j]))j=f[j]; 36 if (p[i]==t[j]) 37 { 38 if (j==m-1)printf("%lld\n",i-m+2); 39 j++; 40 } 41 } 42 }
