Submission #5808788

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
#define ri register int
#define N 200500

struct edge{
  int u,v,l;
	bool operator < (const edge &rhs) const {
	  return l<rhs.l;
	}
} e[N<<1];
int f[N],v[N];
int n,m;
LL ans;

int findroot(int x){
  if (f[x]==x) return x;
	return f[x]=findroot(f[x]);
}

using namespace std;
int main(){
  scanf("%d %d",&n,&m);
	memset(v,0x3f,sizeof(v));
	for (ri i=1;i<=m;i++) {
	  scanf("%d %d %d",&e[i].u,&e[i].v,&e[i].l);
		if (e[i].u==e[i].v) {
		  e[i].u++; e[i].u%=n;
			e[i].l++;
		}
		v[e[i].u]=min(e[i].l+1,v[e[i].u]);
		v[e[i].v]=min(e[i].l+2,v[e[i].v]);
	}
	for (ri i=0;i<n;i++) f[i]=i;
	for (ri i=0;i<2*n;i++) v[(i+1)%n]=min(v[(i+1)%n],v[i%n]+2);
	sort(e+1,e+m+1);
	LL ans=e[1].l;
	int r1=findroot(e[1].u),r2=findroot(e[1].v); f[r1]=r2;
	int cc=m;
	for (ri i=0;i<n-1;i++) e[++cc]=(edge){i,i+1,v[i]};
	e[++cc]=(edge){n-1,0,v[n-1]};
	sort(e+1,e+cc+1);

	for (ri i=1;i<=cc;i++) {
	  int r1=findroot(e[i].u),r2=findroot(e[i].v);
		if (r1==r2) continue;
		f[r1]=r2;
		ans+=e[i].l;
	}
	cout<<ans<<endl;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:26:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&n,&m);
                       ^
./Main.cpp:29:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d %d",&e[i].u,&e[i].v,&e[i].l);
                                             ^

Judge Result