Submission #1694968

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Source Code Expand

#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <memory.h>

using namespace std;
typedef long long LL;
const int maxn = 200005;

int ehead[maxn],ecnt;
struct edge {
	int u,v,next;
}edg[maxn<<1];
void add(int u,int v) {
	edg[++ecnt]=(edge){u,v,ehead[u]};
	ehead[u]=ecnt;
	edg[++ecnt]=(edge){v,u,ehead[v]};
	ehead[v]=ecnt;
}
char s[maxn];int n,low[maxn],high[maxn];LL ans;
int fa[maxn],f[maxn],g[maxn],stk[maxn],top,pos[maxn],idx;
void upd(int &x,int y) {x<y?x=y:0;}
void dfs(int u) {
	pos[++idx]=u;
	for (int v,j=ehead[u];j;j=edg[j].next)
	if ((v=edg[j].v)!=fa[u]) {
		fa[v]=u;dfs(v);f[u]=max(f[u],f[v]+1);
	}
}
void solve(int u) {
	int mx1=0,mx2=0,cur;top=0;
	g[u]>mx1?(mx2=mx1,mx1=g[u]):(g[u]>mx2?mx2=g[u]:0);
	for (int v,j=ehead[u];j;j=edg[j].next)
		if ((v=edg[j].v)!=fa[u]) stk[++top]=v;
	cur=g[u];
	for (int j=1;j<=top;j++) {
		int res=f[stk[j]]+1;
		res>mx1?(mx2=mx1,mx1=res):(res>mx2?mx2=res:0);
		upd(g[stk[j]],cur+1);upd(cur,res);
	}
	cur=g[u];
	for (int j=top;j>=1;j--) {
		int res=f[stk[j]]+1;
		upd(g[stk[j]],cur+1);upd(cur,res);
	}
	high[u]=min(mx1-1,mx2+1);
}
int main()
{
	#ifdef Amberframe
		freopen("agc008f.in","r",stdin);
		freopen("agc008f.out","w",stdout);
	#endif
	scanf("%d",&n);
	for (int u,v,i=1;i<n;i++)
		scanf("%d %d",&u,&v),add(u,v);
	scanf("%s",s+1);dfs(1);
	for (int i=1;i<=n;i++) solve(pos[i]);
	for (int i=1;i<=n;i++)
		ans+=max(0,high[i]-low[i]+1);
	printf("%lld",ans+1);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:54:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:56:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&u,&v),add(u,v);
                                ^
./Main.cpp:57:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s+1);dfs(1);
                 ^

Judge Result