Greedy Termite

不是很难，就是写着有点费劲。

#include<bits/stdc++.h>
#include<algorithm>
#include<iostream>
using namespace std;
typedef long long ll;
typedef long double lf;
typedef pair<int,int>P;
const int inf = 0x7f7f7f7f;
const int N = 1e5+10;
const ll mod = 2012;
const double PI = 3.14;int read(){char ch=getchar();int x=0,f=1;while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while('0'<=ch&&ch<='9'){x=x*10+ch-'0';ch=getchar();}return x*f;
}
int random(int n){return(ll)rand()*rand()%n;}ll x[N],h[N];
ll tree1[N<<5],tree2[N<<5];
ll lazy1[N<<5],lazy2[N<<5];
ll x1,x2;void pushup(int rt){if(tree1[2*rt] > tree1[2*rt+1]){tree1[rt] = tree1[2*rt];lazy1[rt] = lazy1[2*rt];}if(tree1[2*rt] < tree1[2*rt+1]){tree1[rt] = tree1[2*rt+1];lazy1[rt] = lazy1[2*rt+1];}if(tree1[2*rt] == tree1[2*rt+1]){tree1[rt] = tree1[2*rt];lazy1[rt] = lazy1[2*rt+1];}if(tree2[2*rt] > tree2[2*rt+1]){tree2[rt] = tree2[2*rt];lazy2[rt] = lazy2[2*rt];}if(tree2[2*rt] < tree2[2*rt+1]){tree2[rt] = tree2[2*rt+1];lazy2[rt] = lazy2[2*rt+1];}if(tree2[2*rt] == tree2[2*rt+1]){tree2[rt] = tree2[2*rt];lazy2[rt] = lazy2[2*rt];}
}
void build(int rt,int left,int right){if(left == right){tree1[rt] = h[left]+x[left];lazy1[rt] = x[left];tree2[rt] = h[left]-x[left];lazy2[rt] = x[left];return;}int mid = (left+right)/2;build(2*rt,left,mid);build(2*rt+1,mid+1,right);pushup(rt);
}
void update(int rt,int left,int right,int k){if(left == right){tree1[rt] = tree2[rt] = -1e18;return;}int mid = (left+right)/2;if(k <= mid) update(2*rt,left,mid,k);else update(2*rt+1,mid+1,right,k);pushup(rt);
}
ll querytree1(int rt,int left,int right,int l,int r){if(left >= l && right <= r){return tree1[rt];}ll cnt = -1e18;int mid = (left+right)/2;if(l <= mid) cnt = max(cnt,querytree1(2*rt,left,mid,l,r));if(r > mid) cnt = max(cnt,querytree1(2*rt+1,mid+1,right,l,r));return cnt;
}
ll querytree2(int rt,int left,int right,int l,int r){if(left >= l && right <= r){return tree2[rt];}ll cnt = -1e18;int mid = (left+right)/2;if(l <= mid) cnt = max(cnt,querytree2(2*rt,left,mid,l,r));if(r > mid) cnt = max(cnt,querytree2(2*rt+1,mid+1,right,l,r));return cnt;
}
void querylazy1(int rt,int left,int right,int l,int r,ll t){if(left >= l && right <= r){if(tree1[rt] == t){x1 = max(x1,lazy1[rt]);}return;}int mid = (left+right)/2;if(l <= mid) querylazy1(2*rt,left,mid,l,r,t);if(r > mid) querylazy1(2*rt+1,mid+1,right,l,r,t);
}
void querylazy2(int rt,int left,int right,int l,int r,ll t){if(left >= l && right <= r){if(tree2[rt] == t){x2 = min(x2,lazy2[rt]);}return;}int mid = (left+right)/2;if(l <= mid) querylazy2(2*rt,left,mid,l,r,t);if(r > mid) querylazy2(2*rt+1,mid+1,right,l,r,t);
}
int main(){/*/and((unsigned)time(0));//freopen("out.txt","w",stdout);//freopen("in.txt","r",stdin);\*/int n = read(),root = read();for(int i = 1;i <= n;i++){x[i] = read();h[i] = read();}build(1,1,n);ll ans = 0;for(int i = 1;i < n;i++){ll ma1 = -1e18,ma2 = -1e18;x1 = -1e18;x2 = 1e18;if(root-1 >= 1){ma1 = querytree1(1,1,n,1,root-1);querylazy1(1,1,n,1,root-1,ma1);ma1 -= x[root];}if(root+1 <= n){ma2 = querytree2(1,1,n,root+1,n);querylazy2(1,1,n,root+1,n,ma2);ma2 += x[root];}update(1,1,n,root);if(ma1 > ma2){ans += abs(x[root]-x1);root = lower_bound(x+1,x+1+n,x1)-x;//  cout<<root<<endl;}if(ma1 < ma2){ans += abs(x[root]-x2);root = lower_bound(x+1,x+1+n,x2)-x;}if(ma1 == ma2){if(abs(x[root]-x1) <= abs(x[root]-x2)){ans += abs(x[root]-x1);root = lower_bound(x+1,x+1+n,x1)-x;}else {ans += abs(x[root]-x2);root = lower_bound(x+1,x+1+n,x2)-x;}}//    cout<<root<<endl;}cout<<ans<<endl;return 0;
}

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问题 J: Greedy Termite

Greedy Termite

不是很难，就是写着有点费劲。

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