小a的排列
https://ac.nowcoder.com/acm/contest/317/G
C++版本一
std
題解:模擬,思維
#include<bits/stdc++.h> using namespace std; const int MAXN = 1e5 + 10, INF = 1e9 + 10; inline int read() {char c = getchar(); int x = 0, f = 1;while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();return x * f; } void chmin(int &a, int b) {a = (a < b ? a : b);} void chmax(int &a, int b) {a = (a > b ? a : b);} int N, L, R, a[MAXN], pos[MAXN]; int main() { // freopen("a.in", "r", stdin);//freopen("a10.out", "w", stdout);N = read(); L = read(), R = read(); for(int i = 1; i <= N; i++) a[i] = read(), pos[a[i]] = i;L = pos[L]; R = pos[R];if(L > R) swap(L, R);int mx = -1, mn = INF, l = L, r = R;for(int i = L; i <= R; i++) chmin(mn, a[i]), chmax(mx, a[i]);for(int i = mn; i <= mx; i++) chmin(l, pos[i]), chmax(r, pos[i]);while(l < L || R < r){int tmn = mn, tmx = mx;while(l < L) chmin(tmn, a[--L]), chmax(tmx, a[L]);while(R < r) chmin(tmn, a[++R]), chmax(tmx, a[R]);for(int i = tmn; i <= mn; i++) chmin(l, pos[i]), chmax(r, pos[i]);for(int i = mx; i <= tmx; i++) chmin(l, pos[i]), chmax(r, pos[i]);mn = tmn; mx = tmx;}cout << l << ' ' << r;return 0; }?
總結