mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
71 lines
1.7 KiB
C++
71 lines
1.7 KiB
C++
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#include<iostream>
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#include<cstdio>
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#include<cstring>
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#include<cmath>
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#include<algorithm>
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using namespace std;
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const double eps = 1e-7;
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struct node{
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node(){}
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node(double _size,double _rem):size(_size),rem(_rem){}
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double size,rem;
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};
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node Q[1005],data[20005];
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bool cmp(node a,node b)
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{
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if(fabs(a.size-b.size) < eps) return a.rem > b.rem;
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return a.size < b.size;
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}
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double solve(int n,int m,double b)
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{
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int len = 0;
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double ans = 0;
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for(int i = 0;i < n;++i)
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{
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if(len < m)
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{
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double Size = data[i].size*(1-data[i].rem*0.01);
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if(fabs(Size) < eps) continue;
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Q[len++] = node(Size,0.0);
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for(int j = len-1;j > 0;--j)
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{
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if(Q[j].size < Q[j-1].size)
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swap(Q[j],Q[j-1]);
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else
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break;
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}
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}
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if(len == m)
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{
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double t = Q[0].size / (b / m),s = Q[0].size;
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ans += t;
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for(int j = 1;j < len;++j)
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{
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Q[j].size -= s;
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Q[j-1] = Q[j];
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}
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len--;
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}
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}
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for(int i = 0;i < len;++i)
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{
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double t = Q[i].size / (b / (len-i)),s = Q[i].size;
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ans += t;
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for(int j = i;j < len;++j)
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Q[j].size -= s;
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}
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return ans;
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}
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int main()
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{
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int n,m,b,casenum = 1;
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while(scanf("%d%d%d",&n,&m,&b) && n+m+b)
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{
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for(int i = 0;i < n;++i)
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scanf("%lf%lf",&data[i].size,&data[i].rem);
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sort(data,data+n,cmp);
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printf("Case %d: %.2lf\n\n",casenum++,solve(n,m,(double)b));
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}
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return 0;
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}
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