#include <stdio.h>
#define min(a, b) ((a) < (b) ? (a) : (b))
#define max(a, b) ((a) > (b) ? (a) : (b))
#define MAX_N 1000000
int where[MAX_N+1];
int main(void)
{
int n;
int i;
int w;
long long ans = 0;
int left, right;
int left_lim, right_lim;
scanf("%d", &n);
for (i = 1; i <= n; i++) {
int a;
scanf("%d", &a);
where[a] = i;
}
ans = 1;
left = right = where[n];
for (i = 2; i <= n; i++) {
w = where[n - i/2];
left = min(left, w);
right = max(right, w);
left_lim = max(1, right - i + 1);
right_lim = min(n - i + 1, left);
if (left_lim <= right_lim)
ans += right_lim - left_lim + 1;
}
printf("%d %lld\n", 2 * n + 1, ans);
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | #include <stdio.h> #define min(a, b) ((a) < (b) ? (a) : (b)) #define max(a, b) ((a) > (b) ? (a) : (b)) #define MAX_N 1000000 int where[MAX_N+1]; int main(void) { int n; int i; int w; long long ans = 0; int left, right; int left_lim, right_lim; scanf("%d", &n); for (i = 1; i <= n; i++) { int a; scanf("%d", &a); where[a] = i; } ans = 1; left = right = where[n]; for (i = 2; i <= n; i++) { w = where[n - i/2]; left = min(left, w); right = max(right, w); left_lim = max(1, right - i + 1); right_lim = min(n - i + 1, left); if (left_lim <= right_lim) ans += right_lim - left_lim + 1; } printf("%d %lld\n", 2 * n + 1, ans); return 0; } |
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