/* -*- coding: utf-8 -*- * * 1115.cc: No.1115 二つの数列 / Two Sequences - yukicoder */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; /* constant */ const int MAX_N = 100000; /* typedef */ typedef long long ll; /* global variables */ int as[MAX_N], bps[MAX_N], aps[MAX_N], tmp[MAX_N]; ll merge_sort(int as[], int tmp[], int l, int r) { // [l, r) ll ic = 0; if (l + 1 < r) { int m = (l + r) / 2; ic = merge_sort(as, tmp, l, m) + merge_sort(as, tmp, m, r); int i = l, j = m, k = l; while (i < m && j < r) { if (as[i] <= as[j]) tmp[k++] = as[i++]; else tmp[k++] = as[j++], ic += m - i; } while (i < m) tmp[k++] = as[i++]; while (j < r) tmp[k++] = as[j++]; for (int i = l; i < r; i++) as[i] = tmp[i]; } return ic; } /* subroutines */ /* main */ int main() { int n; scanf("%d", &n); for (int i = 0; i < n; i++) scanf("%d", as + i), as[i]--; for (int i = 0; i < n; i++) { int bi; scanf("%d", &bi); bi--; bps[bi] = i; } for (int i = 0; i < n; i++) aps[i] = bps[as[i]]; //for (int i = 0; i < n; i++) printf("%d ", aps[i]); putchar('\n'); ll ic = merge_sort(aps, tmp, 0, n); printf("%lld\n", ic); return 0; }