#include <cstdio> #include <cassert> #include <algorithm> #include <vector> using namespace std; const int max_n = 1000020; vector<int> t; vector<int> tpos (max_n); int n; long long result; void addresults(int l, int r, int maxsize) { int size, df; int a,b; size = r-l+1; df = maxsize-size; a = max(0,l+maxsize-n); b = min(df,l); if (b-a+1 > 0) { result += b-a+1; } } void calc() { int l, r, e; result = 0; l = r = tpos[n]; result++; // printf("result (%d, %d)\n", l, r); if (n % 2 == 0) { e = n/2; } else { e = (n+1)/2; } for(int i = n-1; i >= e; --i) { int j, pos; pos = tpos[i]; if (pos < l) { l = pos; } else { if (pos > r) { r = pos; } } j = n-i; addresults(l, r, 2*j); if (2*j+1 <= n) { addresults(l, r, 2*j+1); } } } int main() { // int nt; // scanf("%d\n", &nt); // for(int j = 0; j < nt; ++j) { // t.clear(); scanf("%d\n", &n); for(int i = 0; i < n; ++i) { int x; scanf("%d\n", &x); t.push_back(x); tpos[x] = i; } if (n < 3) { printf("%d %d\n", 2*n+1, n); return 0; } calc(); printf("%d %lld\n", 2*n+1, result); // } 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 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 | #include <cstdio> #include <cassert> #include <algorithm> #include <vector> using namespace std; const int max_n = 1000020; vector<int> t; vector<int> tpos (max_n); int n; long long result; void addresults(int l, int r, int maxsize) { int size, df; int a,b; size = r-l+1; df = maxsize-size; a = max(0,l+maxsize-n); b = min(df,l); if (b-a+1 > 0) { result += b-a+1; } } void calc() { int l, r, e; result = 0; l = r = tpos[n]; result++; // printf("result (%d, %d)\n", l, r); if (n % 2 == 0) { e = n/2; } else { e = (n+1)/2; } for(int i = n-1; i >= e; --i) { int j, pos; pos = tpos[i]; if (pos < l) { l = pos; } else { if (pos > r) { r = pos; } } j = n-i; addresults(l, r, 2*j); if (2*j+1 <= n) { addresults(l, r, 2*j+1); } } } int main() { // int nt; // scanf("%d\n", &nt); // for(int j = 0; j < nt; ++j) { // t.clear(); scanf("%d\n", &n); for(int i = 0; i < n; ++i) { int x; scanf("%d\n", &x); t.push_back(x); tpos[x] = i; } if (n < 3) { printf("%d %d\n", 2*n+1, n); return 0; } calc(); printf("%d %lld\n", 2*n+1, result); // } return 0; } |