Codeforces Round #305 (Div. 2).D

547B.Mike and Feet

link:http://codeforces.com/contest/548/problem/D

维护一个单调递增的栈, 来记录每个数最大的范围是多少(这样的话要用到map来离散化,但是这样其实是没什么必要的,直接换成i大的范围最大的是多少,这样更快一点)

这代码写的比较挫, 还请见谅.

我其实是故意不写注释的…(逃

#include <cmath>#include <cstdlib>#include <cstdio>#include <cstring>#include <algorithm>#include <string>#include <map>#include <vector>#include <set>#include <queue>#include <stack>#include <iostream>#define LL long long#define pb push_back#define lb lower_bound#define eps 1e-8#define INF 0x3f3f3f3fusing namespace std;const int N = 200005;int a[N], n;map<int, int> mp;struct node{    int x;    int l, r;    node(){}    node(int aa, int bb, int cc){x = aa; l = bb; r = cc;}}stk[N];int top = 0;void solve(){    for(int i=1; i<=n+1; i++){        if(top == 0) stk[top++] = (node){a[i], i, i};        else{            if(a[i] < stk[top-1].x){                int tl, tr = stk[top-1].r;                while(a[i] < stk[top-1].x && top>0){                    node t = stk[--top];                    if(mp.find(t.x) == mp.end()) mp[t.x] = 0;                    mp[t.x] = max(mp[t.x], tr - t.l + 1);                    tl = t.l;                }                stk[top++] = (node){a[i], tl, i};            }            else stk[top++] = (node){a[i], i, i};        }    }    map<int, int>::iterator it = mp.end();    it--;    for(int i=1; i<=n; i++)    {        if(i>1) printf(" ");        if(it->second >= i) printf("%d", it->first);        else{            while(it->second < i && it != mp.begin()) it--;            printf("%d", it->first);        }    }}void input(){    scanf("%d", &n);    for(int i=1; i<=n; i++)  scanf("%d", a+i);    a[n+1] = 0;    mp.clear();    solve();}int main(void){    #ifdef DK        freopen("C:\\Users\\dell\\Desktop\\1.in","r",stdin);    #endif // DK    input();    return 0;}