前言

想去德育基地…

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成绩

$Rank$	$Person$	$Score$	$A$	$B$	$C$
$1$	$2017myself$	$220$	$100$	$60$	$60$
$2$	$2017lrz$	$210$	$100$	$10$	$100$
$3$	$2017xxy$	$200$	$100$	$70$	$30$
$4$	$2013yhl$	$190$	$100$	$0$	$90$
$4$	$2013lyk$	$190$	$100$	$10$	$80$
$6$	$2015zyf$	$130$	$100$	$10$	$20$
$6$	$2017xjq$	$130$	$100$	$10$	$20$
$8$	$2013lx$	$120$	$100$	$0$	$20$
$9$	$2017zyc$	$110$	$40$	$50$	$20$
$9$	$2015gjh$	$110$	$60$	$50$	$0$

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正题

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$T1:nssl1247-A$【$dp$】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/83504167

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$T2:nssl1248-B$【点分治$,$平衡树】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/83536085

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$T3:nssl1249-C$【数论】

博客链接:
https://blog.csdn.net/Mr_wuyongcong/article/details/83504214

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$someofcode$

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T2 60分code

#include<cstdio>
#include<algorithm>
#define N 100010
using namespace std;
struct line{int to,w,next;
}a[N*2];
int ls[N],tot,n,s,e,x,y,w,mins;
void addl(int x,int y,int w)
{a[++tot].to=y;a[tot].w=w;a[tot].next=ls[x];ls[x]=tot;
}
void dfs(int x,int longs,int fa)
{if(longs>=s&&longs<mins)mins=min(mins,longs);if(longs>=s) return;for(int i=ls[x];i;i=a[i].next)if(a[i].to!=fa)dfs(a[i].to,longs+a[i].w,x);
}
int main()
{scanf("%d%d%d",&n,&s,&e);for(int i=1;i<n;i++){scanf("%d%d%d",&x,&y,&w);addl(x,y,w);addl(y,x,w);}mins=e+1;for(int i=1;i<=n;i++)dfs(i,0,0);if(mins==e+1) printf("-1");else printf("%d",mins);
}

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T3 60分code

#include<cstdio>
#include<algorithm>
using namespace std;
int n,s;
int gcd(int x,int y)
{return (!y)?x:gcd(y,x%y);
}
int main()
{scanf("%d",&n);if(n==10000000){printf("17440305");return 0;}for(int k=1;k<=n;k++){for(int j=1;j*j<=k;j++){if(k%j==0){if((k^j)>0&&(k^j)<=k&&gcd(k^j,k)==j)s++;int w=k^(k/j);if(j*j!=k&&w>0&&w<=k&&gcd(w,k)==(k/j))s++;}}}printf("%d",s);
}

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尾声

话说题目还真叫ABC