mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
54 lines
1.1 KiB
C++
54 lines
1.1 KiB
C++
#include <iostream>
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#include <cstring>
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#include <string>
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#include <cstdio>
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#include <cmath>
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#include <algorithm>
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#include <vector>
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#include <queue>
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#include <map>
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#include<stack>
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#define inf 0x3f3f3f3f
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#define ll long long
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#define mod 1000000007
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using namespace std;
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double ans;
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double visit[1005][1005];
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double dfs(int ji,int ou)
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{
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if(ji+ou<=0)return 0;
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if(visit[ji][ou])return visit[ji][ou];
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if(ji%2==1)
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return visit[ji][ou]=dfs(ji-1,ou);
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if(ji)
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{
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if(ou)
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return visit[ji][ou]=(dfs(ji-1,ou)*ji+dfs(ji,ou-1)*ou)/(ji+ou)+ji+ou;
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else
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return visit[ji][ou]=dfs(ji-1,ou)+ji+ou;
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}
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return visit[ji][ou]=dfs(ji,ou-1)+ji+ou;
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}
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int main()
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{
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int t;
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scanf("%d",&t);
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while(t--)
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{
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memset(visit,0,sizeof(visit));
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ans=0;
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int n;
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scanf("%d",&n);
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int ji=0,ou=0;
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for(int i=0; i<n; i++)
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{
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int a;
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scanf("%d",&a);
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if(a%2)ji++;
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else ou++;
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}
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ans=dfs(ji,ou);
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printf("%d\n",(int)(3*ans+0.5));
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}
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}
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