Submission #317877

#	Time	Username	Problem	Language	Result	Execution time	Memory
317877		tincamatei	Mountains (IOI17_mountains)	C++14	20 / 100	1 ms	384 KiB

mountains

#include "mountains.h"
#include <vector>

const int MAX_N = 2000;
int dp[MAX_N];

long long ccw(int x1, int y1, int x2, int y2, int x3, int y3) {
    return (long long)x1 * y2 +
           (long long)x2 * y3 +
           (long long)x3 * y1 -
           (long long)x1 * y3 -
           (long long)x2 * y1 -
           (long long)x3 * y2;
}

int maximum_deevs(std::vector<int> y) {
	int res = 1;
    for(int i = 0; i < y.size(); ++i) {
        dp[i] = 1;
        
        int best = i - 1;
        for(int j = i - 1; j >= 0; --j) {
            if(ccw(i, y[i], best, y[best], j, y[j]) <= 0)
                best = j;
            else
                dp[i] = std::max(dp[j] + 1, dp[i]);
        }

        res = std::max(res, dp[i]);
    }
    return res;
}

Compilation message (stderr)

mountains.cpp: In function 'int maximum_deevs(std::vector<int>)':
mountains.cpp:18:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for(int i = 0; i < y.size(); ++i) {
      |                    ~~^~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30