Codeforces 527C Glass Carving

C. Glass Carving
time limit per test
 2 seconds
memory limit per test
 256 megabytes
input
 standard input
output
 standard output
Leonid wants to become a glass carver (the person who creates beautiful artworks by cutting the glass). He already has a rectangular wmm  ×  h mm sheet of glass, a diamond glass cutter and lots of enthusiasm. What he lacks is understanding of what to carve and how.
In order not to waste time, he decided to practice the technique of carving. To do this, he makes vertical and horizontal cuts through the entire sheet. This process results in making smaller rectangular fragments of glass. Leonid does not move the newly made glass fragments. In particular, a cut divides each fragment of glass that it goes through into smaller fragments.
After each cut Leonid tries to determine what area the largest of the currently available glass fragments has. Since there appear more and more fragments, this question takes him more and more time and distracts him from the fascinating process.
Leonid offers to divide the labor — he will cut glass, and you will calculate the area of the maximum fragment after each cut. Do you agree?
Input
The first line contains three integers w, h, n (2 ≤ w, h ≤ 200 000, 1 ≤ n ≤ 200 000).
Next n lines contain the descriptions of the cuts. Each description has the form H y or V x. In the first case Leonid makes the horizontal cut at the distance y millimeters (1 ≤ y ≤ h - 1) from the lower edge of the original sheet of glass. In the second case Leonid makes a vertical cut at distance x (1 ≤ x ≤ w - 1) millimeters from the left edge of the original sheet of glass. It is guaranteed that Leonid won't make two identical cuts.
Output
After each cut print on a single line the area of the maximum available glass fragment in mm2.
Sample test(s)
input

4 3 4
H 2
V 2
V 3
V 1

output

8
4
4
2

input

7 6 5
H 4
V 3
V 5
H 2
V 1

output

28
16
12
6
4

Note
Picture for the first sample test:
Picture for the second sample test:
문제풀이 사고방식: 두 개의 set으로 각각 길이와 너비의 절단점을 기록하고 두 개의 멀티set으로 절단 후의 길이와 너비 중 구간의 길이를 기록한다.
처음에 길이와 너비의 경계와 길이를 set과 multiset에 삽입한 다음에set에 절단점을 삽입하고find로 그 위치를 찾아내 인접한 절단점(a, b)을 확정하고 해당하는 multiset에서 하나의 (b-a) 구간을 삭제하면 가장 큰 면적은 두 개의 multiset 중 최대치의 곱셈이다.
set과multiset을 이용하여 우리의 정렬, 조회, 각종 조작을 간소화할 수 있기 때문에 좋은 집합에 사용되는 문제입니다.
muitiset과 set의 차이는 전자는 중복된 값이 나타날 수 있고 후자는 중복된 값이 나타날 수 없다는 데 있다.

#include
#include
#include
#include
using namespace std;
set h;
set w;
multisethis;
multisetwis;
int main (){
    int wi,hi,n;
    while(~scanf("%d%d%d",&wi,&hi,&n)){
        h.clear();
        w.clear();
        his.clear();
        wis.clear();
        h.insert(hi);
        w.insert(wi);
        h.insert(0);
        w.insert(0);
        his.insert(hi);
        wis.insert(wi);
        char o;
        int len;
        while(n--){
                getchar();
            scanf("%c%d",&o,&len);
            //cout<