Submission #37020

#	Time	Username	Problem	Language	Result	Execution time	Memory
37020		nickyrio	Divide and conquer (IZhO14_divide)	C++14	100 / 100	73 ms	42740 KiB

divide

#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = a; i<= b; ++i)
#define FORD(i, a, b) for (int i = a; i>=b; --i)
#define REP(i, a) for (int i = 0; i<a; ++i)
#define N 1001000
#define pp pair<int, int>
#define bit(S, i) (((S) >> i) & 1)
#define IO cin.tie(NULL);cout.tie(NULL);
#define taskname "Test"
#define all(s) s.begin(), s.end()
using namespace std;

long long g[N], dp[N], d[N], x[N], BIT[N];
vector<long long> ranking;
int n;

void UpBIT(int u, long long val) {
    for(; u > 0; u -= u & -u) BIT[u] = max(BIT[u], val);
}

long long GetBIT(int u) {
    long long ans = -1e18;
    for(; u <= n; u += u & -u) ans = max(ans, BIT[u]);
    return ans;
}

int main() {
    //freopen(taskname".inp","r",stdin);
    //freopen(taskname".out","w",stdout);
    IO;
    scanf("%d", &n);
    FOR(i, 1, n) scanf("%lld %lld %lld", &x[i], &g[i], &d[i]);
    FOR(i, 1, n) {
        g[i] += g[i - 1];
        d[i] += d[i - 1];
        ranking.push_back(x[i] - d[i - 1]);
    }
    sort(all(ranking));
    ranking.resize(distance(ranking.begin(), unique(all(ranking))));
 //   for (long long x : ranking) printf("%lld ", x ); putchar('\n');
    FOR(i, 1, n) BIT[i] = -1e18;
    int pos = lower_bound(all(ranking), x[1]) - ranking.begin() + 1;
    UpBIT(pos, 0);
    FOR(i, 1, n) {
        int pos = lower_bound(all(ranking), x[i] - d[i]) - ranking.begin() + 1;
 //       printf("%lld ", x[i] - d[i] + 1);
        dp[i] = max(dp[i - 1], GetBIT(pos) + g[i]);
 //       printf("%lld ", dp[i]);
        if (i == n) break;
        pos = upper_bound(all(ranking), x[i + 1] - d[i]) - ranking.begin();
        UpBIT(pos, - g[i]);
    }
    printf("%lld", dp[n]);
}

Compilation message (stderr)

divide.cpp: In function 'int main()':
divide.cpp:31:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
divide.cpp:32:62: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     FOR(i, 1, n) scanf("%lld %lld %lld", &x[i], &g[i], &d[i]);
                                                              ^

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52