oj.uz

Submission #102542

# Submission time Handle Problem Language Result Execution time Memory
102542 2019-03-25T19:46:37 Z tincamatei Watching (JOI13_watching) C++14
100 / 100
 609 ms 16120 KB 
#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 2000;

int v[MAX_N];
int smallNext[1+MAX_N], bigNext[1+MAX_N];
int dp[1+MAX_N][1+MAX_N];

void getNexts(int n, int w, int *nextP) {
	int lastp = 0;
	for(int i = 0; i < n; ++i) {
		while(lastp < n - 1 && v[lastp + 1] < v[i] + w)
			++lastp;
		nextP[i] = lastp;
	}

	nextP[n] = n - 1;
}

void runDp(int n, int w) {
	getNexts(n, w, smallNext);
	getNexts(n, 2 * w, bigNext);
	
	for(int i = 0; i <= n; ++i)
		for(int j = 0; j <= n; ++j) {
			dp[i][j] = 0;
			if(i > 0)
				dp[i][j] = max(dp[i][j], smallNext[dp[i - 1][j]] + 1);
			if(j > 0)
				dp[i][j] = max(dp[i][j], bigNext[dp[i][j - 1]] + 1);
		}
}

int main() {
#ifdef HOME
	FILE *fin = fopen("input.in", "r");
	FILE *fout = fopen("output.out", "w");
#else
	FILE *fin = stdin;
	FILE *fout = stdout;
#endif

	int n, p, q, st, dr;
	
	fscanf(fin, "%d%d%d", &n, &p, &q);
	for(int i = 0; i < n; ++i)
		fscanf(fin, "%d", &v[i]);

	sort(v, v + n);

	st = 0;
	dr = 1000000000;

	while(dr - st > 1) {
		int mid = (st + dr) / 2;
		runDp(n, mid);
		
		if(dp[min(p, n)][min(q, n)] == n)
			dr = mid;
		else
			st = mid;
	}
	
	fprintf(fout, "%d", dr);

	fclose(fin);
	fclose(fout);
	return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:47:8: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  fscanf(fin, "%d%d%d", &n, &p, &q);
  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:49:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   fscanf(fin, "%d", &v[i]);
   ~~~~~~^~~~~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 768 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 5 ms 768 KB Output is correct
5 Correct 5 ms 872 KB Output is correct
6 Correct 4 ms 768 KB Output is correct
7 Correct 4 ms 760 KB Output is correct
8 Correct 4 ms 768 KB Output is correct
9 Correct 4 ms 768 KB Output is correct
10 Correct 4 ms 768 KB Output is correct
11 Correct 4 ms 768 KB Output is correct
12 Correct 4 ms 768 KB Output is correct
13 Correct 4 ms 768 KB Output is correct
14 Correct 4 ms 768 KB Output is correct
15 Correct 3 ms 768 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 589 ms 16052 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 570 ms 16120 KB Output is correct
4 Correct 572 ms 16120 KB Output is correct
5 Correct 585 ms 16120 KB Output is correct
6 Correct 581 ms 16092 KB Output is correct
7 Correct 596 ms 16072 KB Output is correct
8 Correct 601 ms 16120 KB Output is correct
9 Correct 600 ms 16120 KB Output is correct
10 Correct 601 ms 16120 KB Output is correct
11 Correct 599 ms 16120 KB Output is correct
12 Correct 609 ms 16120 KB Output is correct
13 Correct 600 ms 16072 KB Output is correct
14 Correct 593 ms 16120 KB Output is correct
15 Correct 596 ms 16084 KB Output is correct