by hansang:

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=1e4+10;
double t[N], d[N];
int main(){
    int n; scanf("%d", &n);
    int len1=0, len2=0;
    for(int i=1; i<=n; i++){
        char s[5]; double x;
        scanf("%s%lf", s, &x);
        if(s[0]=='T') t[++len1]=x;
        else d[++len2]=x;
    }
    sort(t+1, t+len1+1); sort(d+1, d+len2+1);
    double tmp=0, dis=0, sum=1; int p1=1, p2=1;
    while(p1<=len1 || p2<=len2){
        if((p2>len2) || ((t[p1]-tmp)<(d[p2]-dis)*sum && p1<=len1)){
            dis+=(t[p1]-tmp)/sum;
            tmp=t[p1]; p1++;
        }
        else{
            tmp+=(d[p2]-dis)*sum;
            dis=d[p2]; p2++;
        }
        sum++;
    }
    printf("%.0lf\n", tmp+(1000-dis)*(sum));
    return 0;
}

by hansang:

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=1e4+10;
double t[N], d[N];
int main(){
    int n; scanf("%d", &n);
    int len1=0, len2=0;
    for(int i=1; i<=n; i++){
        char s[5]; double x;
        scanf("%s%lf", s, &x);
        if(s[0]=='T') t[++len1]=x;
        else d[++len2]=x;
    }
    sort(t+1, t+len1+1); sort(d+1, d+len2+1);
    double tmp=0, dis=0, sum=1; int p1=1, p2=1;
    while(p1<=len1 || p2<=len2){
        if((p2>len2) || ((t[p1]-tmp)<(d[p2]-dis)*sum && p1<=len1)){
            dis+=(t[p1]-tmp)/sum;
            tmp=t[p1]; p1++;
        }
        else{
            tmp+=(d[p2]-dis)*sum;
            dis=d[p2]; p2++;
        }
        sum++;
    }
    printf("%.0lf\n", tmp+(1000-dis)*(sum));
    return 0;
}