Submission #3417507

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define ll long long 

const int maxn=500010, inf=1e9;
struct edge{int too, pre;}e[maxn];
int n, m, x, y, tot;
int fa[maxn], a[maxn], b[maxn], last[maxn], pos[maxn];
ll ad[maxn], sum[maxn];
bool v[maxn];
template<typename T>
inline void read(T &k)
{
	int f=1; k=0; char c=getchar();
	while(c<'0' || c>'9') c=='-'&&(f=-1), c=getchar();
	while(c<='9' && c>='0') k=k*10+c-'0', c=getchar();
	k*=f;
}
inline void add(int x, int y){e[++tot]=(edge){y, last[x]}; last[x]=tot;}
inline bool cmp(int x, int y){return a[x]<a[y];}
int gf(int x){return fa[x]==x?x:fa[x]=gf(fa[x]);}
int main()
{
	read(n); read(m);
	for(int i=1;i<=n;i++) read(a[i]), read(b[i]), a[i]=max(a[i]-b[i], 0);
	for(int i=1;i<=m;i++) read(x), read(y), add(x, y), add(y, x);
	for(int i=1;i<=n;i++) pos[i]=i, fa[i]=i, ad[i]=a[i], sum[i]=b[i];
	sort(pos+1, pos+1+n, cmp);
	for(int i=1;i<=n;i++)
	{
		int x=pos[i]; v[x]=1;
		for(int j=last[x], too;j;j=e[j].pre)
		if(v[too=e[j].too])
		{
			int fx=gf(x), fy=gf(too);
			if(fx==fy) continue;
			sum[fx]+=sum[fy]; fa[fy]=fx;
			ad[fx]=min(ad[fx], ad[fy]+max(0ll, a[x]-ad[fy]-sum[fy]));
		}
	}
	printf("%lld\n", sum[pos[n]]+ad[pos[n]]);
	return 0;
}

Submission Info

Judge Result