hdu 1394 水题

本来以为是求逆序数,要用归并排序,而且还得用线段树动态维护神马的,睁大眼睛一看,我滴妈呀,n才5000,直接暴力过了~~

/*
* hdu1394/linux.cpp
* Created on: 2011-9-6
* Author : ben
*/
#include
<cstdio>
#include
<cstdlib>
#include
<cstring>
#include
<cmath>
#include
<algorithm>
using namespace std;

const int MAXN = 5010;
int num[MAXN], reserve[MAXN];

void work();
int main() {
#ifndef ONLINE_JUDGE
freopen(
"data.in", "r", stdin);
#endif
work();
return 0;
}

void work() {
int N, totalres, temp;
while (scanf("%d\n", &N) == 1) {
for (int i = 0; i < N; i++) {
scanf(
"%d", &num[i]);
}
totalres
= 0;
memset(reserve,
0, sizeof(reserve));
for (int i = 0; i < N; i++) {
for (int j = i + 1; j < N; j++) {
if (num[i] > num[j]) {
reserve[i]
++;
}
}
totalres
+= reserve[i];
}
temp
= totalres;
for (int i = 0; i < N; i++) {
temp
+= N - 2 * reserve[i] - 1;
if (temp < totalres) {
totalres
= temp;
}
for (int j = i + 1; j < N; j++) {
if (num[j] > num[i]) {
reserve[j]
++;
}
}
}
printf(
"%d\n", totalres);
}
}
posted @ 2011-09-06 19:17  moonbay  阅读(196)  评论(0编辑  收藏  举报