500 Агент - динамика

#include <iostream>
#include <algorithm>

using namespace std;

struct agent
{
    int age;
    int danger;
};

int compare(agent a, agent b)
{ return a.age < b.age; }

int main( )
{
    FILE *in = fopen("input.txt", "rt"),
            *out = fopen("output.txt", "wt");


    int n;
    fscanf(in, "%d", &n);

    agent potok[n];
    for (int i = 0; i < n; ++i)
    {
        fscanf(in, "%d %d", &potok[i].age, &potok[i].danger);
    }

    sort(potok, potok + n, compare);
    int d[n];
    d[1] = potok[1].danger;
    d[2] = d[1] + potok[2].danger;
    for (int i = 3; i < n; ++i)
    {
        d[i] = min(d[i-1], d[i-2]) + potok[i].danger;
    }

    fprintf(out, "%d", d[n - 1]);
    fclose(in);
    fclose(out);
    return 0;
}