제출 #124280

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
124280		imyujin	Two Antennas (JOI19_antennas)	C++14	100 / 100	966 ms	66064 KiB

antennas

#include<stdio.h>
#include<vector>
#include<algorithm>

using namespace std;

#define MAXN 200005

const int INF = 1 << 30;
int N, Q;
int H[MAXN], A[MAXN], B[MAXN], L[MAXN], R[MAXN];
int ans[MAXN];
int minc[4*MAXN], maxd[4*MAXN], lazy[4*MAXN];
vector<int> query[MAXN], on[2*MAXN], off[2*MAXN];

void spreadlazy(int idx) {
	if(lazy[idx] != -1) {
		lazy[idx * 2] = max(lazy[idx * 2], lazy[idx]);
		lazy[idx * 2 + 1] = max(lazy[idx * 2 + 1], lazy[idx]);
		maxd[idx * 2] = max(maxd[idx * 2], lazy[idx * 2] - minc[idx * 2]);
		maxd[idx * 2 + 1] = max(maxd[idx * 2 + 1], lazy[idx * 2 + 1] - minc[idx * 2 + 1]);
		lazy[idx] = -1;
	}
}

void updc(int idx, int l, int r, int x, int c) {
	//if(idx == 1) printf("updc(x = %d, c = %d)\n", x, c);
	if(l == r) {
		minc[idx] = c;
		lazy[idx] = -1;
		return;
	}
	spreadlazy(idx);
	int m = (l + r) / 2;
	if(x <= m) updc(idx * 2, l, m, x, c);
	else updc(idx * 2 + 1, m + 1, r, x, c);
	minc[idx] = min(minc[idx * 2], minc[idx * 2 + 1]);
	maxd[idx] = max(maxd[idx * 2], maxd[idx * 2 + 1]);
}

void updlazy(int idx, int l, int r, int x, int y, int z) {
	//if(idx == 1) printf("updlazy(x = %d, y = %d, z = %d)\n", x, y, z);
	if(x <= l && r <= y) {
		lazy[idx] = max(lazy[idx], z);
		maxd[idx] = max(maxd[idx], lazy[idx] - minc[idx]);
		return;
	}
	if(r < x || y < l) return;
	spreadlazy(idx);
	int m = (l + r) / 2;
	updlazy(idx * 2, l, m, x, y, z);
	updlazy(idx * 2 + 1, m + 1, r, x, y, z);
	maxd[idx] = max(maxd[idx * 2], maxd[idx * 2 + 1]);
}

int gmaxd(int idx, int l, int r, int x, int y) {
	if(x <= l && r <= y) return maxd[idx];
	if(r < x || y < l) return -1;
	int m = (l + r) / 2;
	spreadlazy(idx);
	return max(gmaxd(idx * 2, l, m, x, y), gmaxd(idx * 2 + 1, m + 1, r, x, y));
}

void print(int x){
	printf("#%d\n", x);
	for(int i = 1; i < 10; i++) 
		printf("i = %d, maxd = %d, minc = %d, lazy = %d\n", i, maxd[i], minc[i], lazy[i]);
	for(int i = 0; i < Q; i++) printf("ans[%d] = %d\n", i, ans[i]);
	printf("\n");
}

void solve() {
	for(int i = 0; i < 2 * N; i++) {
		query[i].clear();
		on[i].clear();
		off[i].clear();
	}
	
	for(int i = 0; i < Q; i++) query[R[i]].push_back(i);
	for(int i = 0; i < N; i++) {
		on[i + A[i]].push_back(i);
		off[i + B[i]].push_back(i);
	}
	for(int i = 1; i < 4 * N; i++) {
		minc[i] = INF;
		maxd[i] = lazy[i] = -1;
	}

	for(int i = 0; i < N; i++) {
		for(auto a : on[i]) updc(1, 0, N-1, a, H[a]);
		//print(1);
		updlazy(1, 0, N-1, i - B[i], i - A[i], H[i]);
		//print(2);
		for(auto a : query[i]) ans[a] = max(ans[a], gmaxd(1, 0, N-1, L[a], i));
		//print(3);
		for(auto a : off[i]) updc(1, 0, N-1, a, INF);
		//print(4);
	}
}

int main() {
	scanf("%d", &N);
	for(int i = 0; i < N; i++) scanf("%d%d%d", H+i, A+i, B+i);
	scanf("%d", &Q);
	for(int i = 0; i < Q; i++) scanf("%d%d", L+i, R+i);

	for(int i = 0; i < Q; i++) {
		ans[i] = -1;
		L[i]--;
		R[i]--;
	}
	solve();
	for(int i = 0; i < N/2; i++){
		swap(H[i], H[N - i - 1]);
		swap(A[i], A[N - i - 1]);
		swap(B[i], B[N - i - 1]);
	}
	for(int i = 0; i < Q; i++) {
		swap(L[i], R[i]);
		L[i] = N - L[i] - 1;
		R[i] = N - R[i] - 1;
	}
	solve();

	for(int i = 0; i < Q; i++) printf("%d\n", ans[i]);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

antennas.cpp: In function 'int main()':
antennas.cpp:102:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
antennas.cpp:103:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 0; i < N; i++) scanf("%d%d%d", H+i, A+i, B+i);
                             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:104:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
antennas.cpp:105:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 0; i < Q; i++) scanf("%d%d", L+i, R+i);
                             ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 65 / 65