[BZOJ1537][POI2005]Aut- The Bus

#include <cstdio>
#include <cstring>
#include <algorithm>
char buf[10000000], *ptr = buf - 1;
inline int readint(){
    int n = 0;
    while(*++ptr < ‘0‘ || *ptr > ‘9‘);
    while(*ptr <= ‘9‘ && *ptr >= ‘0‘) n = (n << 1) + (n << 3) + (*ptr++ & 15);
    return n;
}
const int maxn = 100000 + 10;
inline void max(int &a, const int &b){
    if(a < b) a = b;
}
int n, c[maxn] = {0};
int num[maxn], cnt;
inline int Query(int pos){
    int s = 0;
    for(int i = pos; i; i -= i & -i) max(s, c[i]);
    return s;
}
inline void Update(int pos, int val){
    for(int i = pos; i <= cnt; i += i & -i) max(c[i], val);
}
struct Node{
    int x, y, p;
    bool operator < (const Node &a) const{
        return x == a.x ? y < a.y : x < a.x;
    }
}no[maxn];

int main(){
    buf[fread(buf, sizeof(char), sizeof(buf), stdin)] = 0;
    readint(); readint();
    n = readint();
    for(int i = 1; i <= n; i++){
        no[i].x = readint();
        num[i] = no[i].y = readint();
        no[i].p = readint();
    }
    std::sort(num + 1, num + n + 1);
    cnt = std::unique(num + 1, num + n + 1) - (num + 1);
    for(int i = 1; i <= n; i++)
        no[i].y = std::lower_bound(num + 1, num + cnt + 1, no[i].y) - num;
    std::sort(no + 1, no + n + 1);
    for(int t, i = 1; i <= n; i++){
        t = Query(no[i].y);
        Update(no[i].y, no[i].p + t);
    }
    printf("%d\n", Query(cnt));
    return 0;
}