layout: post
title: 2019 Multi-University Training Contest 1
author: "luowentaoaa"
catalog: true
tags:
mathjax: true
- ACM-ICPC
1001.Blank
题意
1002 Operation(前缀线性基)
原题
#include<bits/stdc++.h>
using namespace std;
const int maxn=1e6+50;
int pos[maxn][32];
int val[maxn][32];
void add(int x,int ans){
for(int i=0;i<=31;i++){
pos[x][i]=pos[x-1][i];
val[x][i]=val[x-1][i];
}
int tmp=x;
for(int i=31;i>=0;i--){
if(ans&(1<<i)){
if(val[x][i]==0){
val[x][i]=ans;
pos[x][i]=tmp;
break;
}
if(pos[x][i]<tmp){
swap(pos[x][i],tmp),swap(val[x][i],ans);
}
ans^=(val[x][i]);
}
}
}
int main(){
int t;
std::ios::sync_with_stdio(false);
cin>>t;
while(t--){
int n,m;
cin>>n>>m;
for(int i=1;i<=n;i++){
int a;
cin>>a;
add(i,a);
}
int last=0;
while(m--){
int op;
cin>>op;
if(op){
n++;
int x;
cin>>x;
x^=last;
add(n,x);
}
else{
int l,r;cin>>l>>r;
l=(l^last)%n+1;
r=(r^last)%n+1;
if(l>r)swap(l,r);
int ans=0;
for(int i=31;i>=0;i--){
if(pos[r][i]>=l&&((ans^val[r][i])>ans))ans=ans^val[r][i];
}
cout<<ans<<endl;
last=ans;
}
}
}
return 0;
}
1003.Milk
1004.Vacation(二分答案)
#include<bits/stdc++.h>
using namespace std;
const int maxn=2e6+50;
const double eps=1e-7;
int l[maxn],s[maxn],v[maxn],n;
double pos[maxn];
bool check(double mid){
pos[n+1]=mid*v[n+1]-s[n+1]-l[n+1];
for(int i=n;i;i--){
if(mid*v[i]-s[i]>=pos[i+1])
pos[i]=pos[i+1]-l[i];
else pos[i]=mid*v[i]-s[i]-l[i];
}
return pos[1]+l[1]>=eps;
}
int main(){
std::ios::sync_with_stdio(false);
while(cin>>n){
for(int i=1;i<=n+1;i++)cin>>l[i];
for(int i=1;i<=n+1;i++)cin>>s[i];
for(int i=1;i<=n+1;i++)cin>>v[i];
double l=0.0,r=1e9,ans;
while(l+eps<=r){
double mid=(l+r)/2.0;
if(check(mid)){
r=mid;
ans=mid;
}
else l=mid;
}
cout<<fixed<<setprecision(10)<<ans<<endl;
}
return 0;
}
1005.Path(网络流+最短路)
#include<bits/stdc++.h>
using namespace std;
const int maxn=2e5+50;
typedef long long ll;
ll S,T,From[maxn],Laxt[maxn],Next[maxn],To[maxn],Cap[maxn],cnt;
ll vd[maxn],dis[maxn];
void add(int u,int v,ll c){
Next[++cnt]=Laxt[u];Laxt[u]=cnt;To[cnt]=v;Cap[cnt]=c;From[cnt]=u;
Next[++cnt]=Laxt[v];Laxt[v]=cnt;To[cnt]=u;Cap[cnt]=0;From[cnt]=v;
}
ll sap(int u,ll flow,ll limit){
if(u==T||flow==0)return flow;
int tmp,delta=0;
for(int i=Laxt[u];i;i=Next[i]){
int v=To[i];
if(dis[u]==dis[v]+1&&Cap[i]){
tmp=sap(v,min(flow-delta,Cap[i]),limit);
Cap[i]-=tmp;Cap[i^1]+=tmp;delta+=tmp;
if(dis[S]>=(limit)||delta==flow)return delta;
}
}
vd[dis[u]]--;if(!vd[dis[u]])dis[S]=limit;
vd[++dis[u]]++;
return delta;
}
void init(int limit){
cnt=1;
for(int i=0;i<=limit;i++)Laxt[i]=dis[i]=vd[i]=0;
}
ll dist1[maxn];
ll dist2[maxn];
ll a[maxn],b[maxn],c[maxn];
struct node{
int u,v;
ll w;
};
struct no{
int id;
ll w;
bool operator <(const no &a)const{
return this->w>a.w;
}
};
vector<node>G[maxn];
void dij(ll d[],int n,int S){
for(int i=1;i<=n;i++)d[i]=1e18;
d[S]=0;
priority_queue<no>Q;
Q.push({S,d[S]});
while(!Q.empty()){
no tmp=Q.top();
Q.pop();
int u=tmp.id;
for(int i=0;i<G[u].size();i++){
node k=G[u][i];
int v=k.v,w=k.w;
if(d[v]>d[u]+w){
d[v]=d[u]+w;
Q.push({v,d[v]});
}
}
}
}
int main(){
std::ios::sync_with_stdio(false);
int t;
cin>>t;
while(t--){
int n,m;
cin>>n>>m;
init(n+2);
for(int i=1;i<=n;i++)G[i].clear();
for(int i=1;i<=m;i++){
cin>>a[i]>>b[i]>>c[i];
G[a[i]].push_back({a[i],b[i],c[i]});
}
S=1;T=n;
dij(dist1,n,S);
for(int i=1;i<=n;i++)G[i].clear();
for(int i=1;i<=m;i++){
G[b[i]].push_back({b[i],a[i],c[i]});
}
dij(dist2,n,T);
for(int i=1;i<=m;i++){
if(a[i]!=b[i]&&dist1[a[i]]+c[i]+dist2[b[i]]==dist1[T]){
add(a[i],b[i],c[i]);
}
}
ll ans=0;
while(dis[S]<n+2){
ans+=sap(S,1e18,n+2);
}
cout<<ans<<endl;
}
return 0;
}