Missing Skyline

#include <bits/stdc++.h>
using namespace std;

int hi[30010];
int main()
{
    int n;
    scanf("%d", &n);
    while (n--) {
        int l, r, h;
        scanf("%d%d%d", &l, &r, &h);
        for (int i = l; i < r; ++i) {
            if (h > hi[i])
                hi[i] = h;
        }
    }
    for (int i = 1; i <= 30000; ++i) {
        if (hi[i] != hi[i-1])
            printf("%d %d\n", i, hi[i]);
    }

    return 0;
}