题意:让你给点连线,再去除所有R点,或B点后都可以实现任意两点互相可达,并且代价最小,两点连线的代码为两点间的距离
题解:我只需要当到达P点的时候要么与前一个p点相连3次然后减取之前R点B点的最大两点距离,或者就直接与前面一个点连接两次取两者最小值即可,其他情况直接与前面一个点相连即可
#include<iostream>
#include<cstring>
#include<algorithm>
#include<queue>
#include<vector>
#include<cstdio>
#include<cmath>
#include<set>
#include<map>
#include<cstdlib>
#include<ctime>
#include<stack>
#include<bitset>
using namespace std;
#define mes(a) memset(a,0,sizeof(a))
#define rep(i,a,b) for(i = a; i <= b; i++)
#define dec(i,a,b) for(i = b; i >= a; i--)
#define fi first
#define se second
#define ls rt<<1
#define rs rt<<1|1
#define lson ls,L,mid
#define rson rs,mid+1,R
typedef double db;
typedef long long int ll;
typedef pair<int,int> pii;
typedef unsigned long long ull;
const ll inf = 1e15;
const int mx = 2e5+5;
const int x_move[] = {1,-1,0,0,1,1,-1,-1};
const int y_move[] = {0,0,1,-1,1,-1,1,-1};
int main(){
int t,q,ca = 1;
int n;
ll pa,pb,pc;
ll ans = 0;
pa = pb = pc = inf;
ll pra = 0,prb = 0;
scanf("%d",&n);
for(int i = 0; i < n; i++){
ll v;
char str[10];
scanf("%I64d%s",&v,str);
if(str[0]=='R'){
if(pa!=inf){
pra = max(pra,v-pa);
ans += v-pa;
}
pa = v;
}
else if(str[0]=='B'){
if(pb!=inf){
prb = max(prb,v-pb);
ans += v-pb;
}
pb = v;
}
else{
if(pb!=inf){
prb = max(prb,v-pb);
ans += v-pb;
}
if(pa!=inf){
pra = max(pra,v-pa);
ans += v-pa;
}
if(pc!=inf)
ans = min(ans,ans+v-pc-pra-prb);
pa = pb = pc = v;
pra = prb = 0;
}
}
printf("%I64d\n",ans);
return 0;
}