这个题 LIS + 并查集的思想 + 链式前向星
要求找s(i,j)使i j 能有最长的LIS 。。。
做法是枚举每一个j 即终点 算 起点 的可能
无力吐槽了 bc 的时候写错了一个地方 导致TLE 后来幡然醒悟了
改了就a了
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不想说什么了 直接上代码
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#include <cstdio> #include <cmath> #include <algorithm> #include <iostream> #include <cstdlib> #include <string> #include <queue> #include <map> #include <stack> #include <cstring> #define CL(a,b) memset(a,b,sizeof(a)) #define ll __int64 #define TEST cout<<"TEST ***"<<endl; #define INF 0x7ffffff0 #define MOD 1000000007 using namespace std;typedef struct node {int p,next; }N; N no[100010]; int head[100010],cv;int num[100010]; int fa[100010]; int pi[100010]; int so[100010],ct; int n;void inithead() {CL(head,-1);cv=0; }void addnode(int s,int e) {no[cv].p=e;no[cv].next=head[s];head[s]=cv++; }void initfa() {int i,j;for(i=0;i<=100000;i++)fa[i]=i; }int finr(int x) {if(fa[x]==x)return x;fa[x]=finr(fa[x]);return fa[x]; }void unio(int x,int y) {int rx=finr(x);int ry=finr(y);fa[rx]=ry; }int bin(int s,int e,int v) {int m=(s+e)/2;if(so[m]>=v&&so[m-1]<v)return m;if(so[m]>v)return bin(s,m,v);return bin(m+1,e,v); }int main() {while(scanf("%d",&n)!=EOF){int i,j,a,p,v;initfa();inithead();so[0]=-1;ct=0;for(i=1;i<=n;i++){scanf("%d",&a);num[i]=a;if(a>so[ct]){ct++;so[ct]=a;addnode(ct,i);pi[i]=ct;}else{p=bin(0,ct,a);so[p]=a;addnode(p,i);pi[i]=p;}if(pi[i]!=1){p=head[pi[i]-1];while(p!=-1){v=no[p].p;if(num[v]<a){unio(i,v);break;}p=no[p].next;}}}ll rem=0,la=0,he;i=n;while(i>=1){la++;if(pi[i]==ct){he=finr(i);rem+=la*he;la=0;}i--;}printf("%I64d\n",rem);}return 0; }
