[51NOD1272]最大距离（贪心）

Posted 2020-08-05

题目链接：http://www.51nod.com/onlineJudge/questionCode.html#!problemId=1272

思路：排序后由于序列都是顺序的，则只需要考虑序号了，加入当前维护的序号比后面的小，则更新ret。否则更新当前序号

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <iomanip>
 4 #include <cstring>
 5 #include <climits>
 6 #include <complex>
 7 #include <fstream>
 8 #include <cassert>
 9 #include <cstdio>
10 #include <bitset>
11 #include <vector>
12 #include <deque>
13 #include <queue>
14 #include <stack>
15 #include <ctime>
16 #include <set>
17 #include <map>
18 #include <cmath>
19 
20 using namespace std;
21 #define fr first
22 #define sc second
23 #define cl clear
24 #define BUG puts("here!!!")
25 #define W(a) while(a--)
26 #define pb(a) push_back(a)
27 #define Rint(a) scanf("%d", &a)
28 #define Rll(a) scanf("%lld", &a)
29 #define Rs(a) scanf("%s", a)
30 #define Cin(a) cin >> a
31 #define FRead() freopen("in", "r", stdin)
32 #define FWrite() freopen("out", "w", stdout)
33 #define Rep(i, len) for(int i = 0; i < (len); i++)
34 #define For(i, a, len) for(int i = (a); i < (len); i++)
35 #define Cls(a) memset((a), 0, sizeof(a))
36 #define Clr(a, p) memset((a), (p), sizeof(a))
37 #define Full(a) memset((a), 0x7f7f7f, sizeof(a))
38 #define lrt rt << 1
39 #define rrt rt << 1 | 1
40 #define pi 3.14159265359
41 #define RT return
42 #define lowbit(p) p & (-p)
43 #define onenum(p) __builtin_popcount(p)
44 typedef long long LL;
45 typedef long double LD;
46 typedef unsigned long long ULL;
47 typedef pair<int, int> pii;
48 typedef pair<string, int> psi;
49 typedef pair<LL, LL> pll;
50 typedef map<string, int> msi;
51 typedef vector<int> vi;
52 typedef vector<LL> vl;
53 typedef vector<vl> vvl;
54 typedef vector<bool> vb;
55 
56 const int maxn = 50500;
57 typedef struct Node {
58     int i, n;
59 }Node;
60 
61 int n;
62 int a[maxn];
63 Node b[maxn];
64 
65 bool cmp(Node x, Node y) {
66     if(x.n == y.n) return x.i < y.i;
67     return x.n < y.n;
68 }
69 
70 int main() {
71     // FRead();
72     while(~Rint(n)) {
73         Rep(i, n) {
74             Rint(a[i]);
75             b[i].n = a[i]; b[i].i = i;
76         }
77         sort(b, b+n, cmp);
78         int ret = 0, cur = b[0].i;
79         For(i, 1, n) {
80             if(b[i].i > cur) ret = max(ret, b[i].i-cur);
81             else cur = b[i].i;
82         }
83         printf("%d\n", ret);
84     }
85     RT 0;
86 }