前言

$Todayisthepenultimateday$

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成绩

$Rank$是有算别人的

$Rank$	$Person$	$Score$	$A$	$B$	$C$
$3$	$2017zyc$	$250$	$90$	$100$	$60$
$10$	$2017xxy$	$220$	$20$	$100$	$100$
$21$	$2017lrz$	$180$	$20$	$100$	$60$
$21$	$2017wyc$	$180$	$30$	$50$	$100$
$54$	$2017xjq$	$110$	$0$	$50$	$60$
$72$	$2017hzb$	$80$	$0$	$20$	$60$
$81$	$2017lw$	$70$	$0$	$10$	$60$
$88$	$2017hjq$	$60$	$0$	$0$	$60$

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正题

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$T1:jzoj4252-$QYQ的图【$dfs$】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/86702752

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$T2:jzoj4248-n$染色【数学,快速幂】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/86703758

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$T3:jzoj4249-$游戏【贪心】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/86703879

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$someofcode$

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T1 30分code

#include<cstdio>
#include<algorithm>
using namespace std;
const int N=60;
int tot,in[N],ans,w[N],flag[N],n,maxs,m;
bool v[N],a[N][N],zh[N];
void dfs(int x)
{in[++tot]=x;v[x]=1;ans+=w[x];for(int i=1;i<=n;i++)if(a[x][i]&&!v[i])dfs(i);
}
void get_ans(int dep,int z)
{if(dep>tot){maxs=max(maxs,z);return;}get_ans(dep+1,z);if(!flag[dep]&&!zh[in[dep]]){for(int i=1;i<=tot;i++)if(a[in[dep]][in[i]])flag[i]++;get_ans(dep+1,z+w[in[dep]]);for(int i=1;i<=tot;i++)if(a[in[dep]][in[i]])flag[i]--;}
}
int main()
{freopen("graph.in","r",stdin);freopen("graph.out","w",stdout);scanf("%d%d",&n,&m);for(int i=1;i<=n;i++)scanf("%d",&w[i]);for(int i=1;i<=m;i++){int x,y;scanf("%d%d",&x,&y);if(x==y) zh[x]=1;a[x][y]=a[y][x]=1;}for(int i=1;i<=n;i++){maxs=0;tot=0;dfs(i);get_ans(1,0);ans-=maxs;}printf("%d",ans);
}

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T2 50分code

#include<cstdio>
#define ll long long
using namespace std;
const ll XJQ=1e9+7;
ll n,m,ans,f[100010][15];
int main()
{freopen("color.in","r",stdin);freopen("color.out","w",stdout);scanf("%lld%lld",&n,&m);f[1][1]=1;for(ll i=2;i<=n+1;i++)for(ll j=1;j<=m;j++)for(ll k=1;k<=m;k++)if(k!=j)(f[i][j]+=f[i-1][k])%=XJQ;printf("%lld",f[n+1][1]*m%XJQ);
}

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总结

爆炸了

T1不会，去写T2，然后写了个错的。之后写T3，开始写dp，后来发现可以贪心，切掉。然后T1写了个暴力(我还证明了暴力可过)，结果写挂了，炸掉30。然后T2找了半天规律，最后二分钟开始写，结果时间不够，只有之前那个50分codeQVQ

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尾声

雷大爷险些$Rank1$