A
题解
代码
B
题解
代码
C
题解
三分,对于怎么看出来三分,这可能是个套路,你觉得这个题你用贪心做不了(但非常像贪心),二分答案会被hack,然后你$dp$也难以做,你三分就可以了
三分$check$贪心做,很水,我会说
代码
/*
n*log^2
*/
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define A 222222
struct node{
ll l,r;
friend bool operator < (const node & a,const node &b){
return a.l==b.l?a.r>b.r:a.l<b.l;
}
}wat[A];
ll n,m,t,ans=0x7fffffffffffff,maxx=0,cnt=0;
ll p[A],lef[A],now[A],c[A];
ll check(ll x){
ll sum=0;
for(ll i=1;i<=n;i++){
now[i]=max(p[i]-x,0ll);
c[i]=0;
}
for(ll i=1;i<=n;i++){
ll nowid=lef[i];
c[i]+=c[i-1];
if(lef[i]==0) continue ;
ll cha=c[i];
// printf("i=%lld c[i]=%lld c[i-1]=%lld\n",i,c[i],c[i-1]);
// printf("i=%lld now+cha=%lld\n",i,now[i]+cha);
if(now[i]+cha>0){
sum+=now[i]+cha;
c[i]-=(now[i]+cha);
c[wat[nowid].r+1]+=now[i]+cha;
now[i]=0;
}
}
for(ll i=1;i<=n;i++){
ll cha=c[i];
// printf("now=%lld x=%lld cha=%lld\n",now[i],x,cha);
if(now[i]+cha>0) return 0x7fffffffff;
}
return sum+x*t;
}
int main(){
// freopen("da.in","r",stdin);
// freopen("ans.bf","w",stdout);
scanf("%lld%lld%lld",&n,&m,&t);
for(ll i=1;i<=n;i++){
scanf("%lld",&p[i]);
maxx=max(maxx,p[i]);
}
for(ll i=1;i<=m;i++){
scanf("%lld%lld",&wat[i].l,&wat[i].r);
}
sort(wat+1,wat+m+1);
for(ll i=1;i<=m;i++){
if(!lef[wat[i].l])
lef[wat[i].l]=i;
}
for(ll i=1;i<=n;i++)
if(wat[lef[i-1]].r>=i){
if(wat[lef[i-1]].r>wat[lef[i]].r)
lef[i]=lef[i-1];
}
ll l=0,r=maxx;
while(l<r){
ll len=(r-l);
ll lmid=l+len/3,rmid=r-len/3;
ll lnow=check(lmid),rnow=check(rmid);
// printf("l=%lld r=%lld\n",l,r);
if(lnow>=rnow) l=lmid+1;
else r=rmid-1;
ans=min(ans,lnow);
ans=min(ans,rnow);
}
// printf("%lld\n",check(5));
printf("%lld\n",ans);
}