Submission #91320

#	Time	Username	Problem	Language	Result	Execution time	Memory
91320		Just_Solve_The_Problem	K blocks (IZhO14_blocks)	C++11	0 / 100	399 ms	3500 KiB

blocks

#include <bits/stdc++.h>

using namespace std;

const int N = (int)1e5 + 7;
const int inf = (int)1e9 + 7;

int n, k;
int dp[2][N];
int a[N];

struct sparse {
	int table[19][N];
	int numlog[N];
	void build() {
		for (int i = 2; i < N; i++) {
			numlog[i] = numlog[i / 2] + 1;
		}
		for (int i = 0; i <= 17; i++) {
			for (int j = 1; j <= n; j++) {
				if (!i) {
					table[i][j] = a[j];
				} else {
					table[i][j] = max(table[i - 1][j], table[i - 1][j + (1 << (i - 1))]);
				}
			}
		}
	}
	int getmax(int l, int r) {
		int lg = numlog[r - l + 1];
		return max(table[lg][l], table[lg][r - (1 << lg) + 1]);
	}
};
sparse table;

void div(int id, int l, int r, int optl, int optr) {
	if (l > r) return ;
	int mid = (l + r) >> 1;
	int &res = dp[id][mid];
	res = inf;
	int opt = optl;
	for (int i = optl; i <= min(mid, optr); i++) {
		int cost = table.getmax(i, mid);
		if (dp[id ^ 1][i - 1] + cost < res) {
			res = dp[id ^ 1][i - 1] + cost;
			opt = i;
		}
	}
	div(id, l, mid - 1, optl, opt);
	div(id, mid + 1, r, opt, optr);
}

int opt[N];

main() {
	scanf("%d %d", &n, &k);
	for (int i = 1; i <= n; i++) {
		scanf("%d", &a[i]);
	}
	table.build();
	for (int i = 1; i <= n; i++) {
		dp[1][i] = max(dp[1][i - 1], a[i]);
	}
	for (int i = 2; i <= k; i++) {
		for (int j = 1; j < i; j++) {
			opt[j] = 0;
		}
		for (int j = i; j <= n; j++) {
			int &res = dp[i & 1][j];
			res = inf;
			for (int l = i - 1; l < j; l++) {
				int cost = table.getmax(l + 1, j) + dp[i & 1 ^ 1][l];
				if (cost <= res) {
					res = cost;
					opt[j] = l;
				}
			}
			assert(opt[j - 1] <= opt[j]);
		}
	}
	cout << dp[k & 1][n];
}
/*
10 6
3 | 9 5 8 | 7 | 3 | 8 6 10 | 2 

10 6
3 9 5 8 7 3 8 6 10 2
ans = 34
*/

Compilation message (stderr)

blocks.cpp:55:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
blocks.cpp: In function 'int main()':
blocks.cpp:72:46: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
     int cost = table.getmax(l + 1, j) + dp[i & 1 ^ 1][l];
                                            ~~^~~
blocks.cpp:56:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &k);
  ~~~~~^~~~~~~~~~~~~~~~~
blocks.cpp:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 18
• Subtask 3: 0 / 21
• Subtask 4: 0 / 47