Orz ydc："这题是我见到的第一道非斜率优化的1D1D了……"
话说ydc神犇认为单调队列不是优化咩？、、、已经给跪了
Orz决策单调性
1 /************************************************************** 2 Problem: 2216 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:4128 ms 7 Memory:16432 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <cmath> 12 #include <algorithm> 13 14 using namespace std; 15 typedef double lf; 16 const int N = 500005; 17 18 struct data { 19 int l, r, p; 20 data() {} 21 data(int _l, int _r, int _p) : l(_l), r(_r), p(_p) {} 22 }q[N]; 23 24 int n, a[N]; 25 lf f[N], g[N]; 26 27 inline int read() { 28 int x = 0, sgn = 1; 29 char ch = getchar(); 30 while (ch < '0' || '9' < ch) { 31 if (ch == '-') sgn = -1; 32 ch = getchar(); 33 } 34 while ('0' <= ch && ch <= '9') { 35 x = x * 10 + ch - '0'; 36 ch = getchar(); 37 } 38 return sgn * x; 39 } 40 41 inline lf calc(int j, int i) { 42 return a[j] - a[i] + sqrt(abs(i - j)); 43 } 44 45 int find(data t, int x) { 46 int l = t.l, r = t.r, mid; 47 while (l <= r) { 48 mid = l + r >> 1; 49 if (calc(t.p, mid) > calc(x, mid)) 50 l = mid + 1; 51 else r = mid - 1; 52 } 53 return l; 54 } 55 56 void dp(lf *F) { 57 for (int i = 1, h = 1, t = 0, tmp; i <= n; ++i) { 58 ++q[h].l; 59 if (h <= t && q[h].r < q[h].l) ++h; 60 if (h > t || calc(i, n) > calc(q[t].p, n)) { 61 while (h <= t && calc(q[t].p, q[t].l) < calc(i, q[t].l)) 62 --t; 63 if (h > t) q[++t] = data(i, n, i); 64 else { 65 tmp = find(q[t], i); 66 q[t].r = tmp - 1; 67 q[++t] = data(tmp, n, i); 68 } 69 } 70 F[i] = calc(q[h].p, i); 71 } 72 } 73 74 int main() { 75 int i; 76 n = read(); 77 for (i = 1; i <= n; ++i) 78 a[i] = read(); 79 dp(f); 80 reverse(a + 1, a + n + 1); 81 dp(g); 82 for (i = 1; i <= n; ++i) 83 printf("%d ", (int) ceil(max(f[i], g[n - i + 1]))); 84 return 0; 85 } 86