BZOJ4619 [Wf2016]Swap Space

来源：互联网发布：动态bgp网络编辑：程序博客网时间：2024/05/25 05:37

把所有硬盘按照格完了之后是容量变大还是变小分成两类，先做变大的，后做变小的，变大的按原容量升序排序，变小的按新容量降序排序

证明感性理解一下就好……

UPD：证明见 BZOJ3709 [PA2014]Bohater

#include<iostream>#include<cstdio>#include<cstdlib>#include<cstring>#include<ctime>#include<cmath>#include<algorithm>#include<iomanip>#include<vector>#include<map>#include<set>#include<bitset>#include<queue>#include<stack>using namespace std;#define MAXN 1000010#define MAXM 1010#define INF 1000000000#define MOD 1000000007#define eps 1e-8#define ll long longstruct db{int x;int y;};db a[MAXN],b[MAXN];int n,tot1,tot2;ll ans,rem;bool cmp1(db x,db y){return x.x<y.x;}bool cmp2(db x,db y){return x.y>y.y;}void cal(int x,int y){rem-=x;if(rem<0){ans-=rem;rem=0;}rem+=y;}int main(){int i,x,y;scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d%d",&x,&y);if(x<y){a[++tot1].x=x;a[tot1].y=y;}else{b[++tot2].x=x;b[tot2].y=y;}}sort(a+1,a+tot1+1,cmp1);sort(b+1,b+tot2+1,cmp2);for(i=1;i<=tot1;i++){cal(a[i].x,a[i].y);}for(i=1;i<=tot2;i++){cal(b[i].x,b[i].y);}printf("%lld\n",ans);return 0;}/*1011 8298 1278 5315 1041 281 5853 4230 4125 3920 54*/

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