HDU 4302 Holedox Eating （multiset模拟）
唉。赛上wa了十来发没能过的水题。。 发个博客纪念一下
题意: 不同的位置会随机出现出的 一个地方可能会出现多个吃的 初始在0 每次去最近的 如果两边距离一样去 之前移动方向的那个
分析: 没啥就是一个multiset或者map模拟的水题 有个trick就是 - - 有可能会被呆在原地的多个吃的 隐藏的修改了方向然后就跪了
数据还是水了 题目里的数据只有一个方向的 如果不判断等于pre也可以过 但是等于nxt的数据是有的
结论: 论仔细思考 然后写出优美代码的重要性!
trick: 这个题目数据里没有 但是也能帮你找到wa点吧
1 20 13 0 4 1 0 3 1 0 3 1 0 1 0 5 0 20 1 1 1 1
代码:
1. 修改wa之后AC的代码
//
// Created by TaoSama on 2015-09-12
// Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>
using namespace std;
#define pr(x) cout << #x << " = " << x << " "
#define prln(x) cout << #x << " = " << x << endl
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;
int n, q;
int main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
// freopen("out.txt","w",stdout);
#endif
ios_base::sync_with_stdio(0);
int t; scanf("%d", &t);
int kase = 0;
while(t--) {
scanf("%d%d", &n, &q);
multiset<int> s;
multiset<int>::iterator lef, rig;
int cur = 0, dir = 1;
long long ans = 0;
while(q--) {
// printf("q: %d\n", q);
int op, x; scanf("%d", &op);
if(op == 0) {
scanf("%d", &x);
s.insert(x);
} else {
if(s.size() == 0) continue;
rig = s.lower_bound(cur);
lef = rig;
int pre = -INF, nxt = INF;
if(rig != s.end()) nxt = *rig;
if(lef != s.begin()) pre = *(--lef);
int dif1 = cur - pre, dif2 = nxt - cur;
// printf("%d %d %d dir: %d\n", pre, cur, nxt, dir);
ans += min(dif1, dif2);
if(dif1 < dif2) {
if(cur != pre) {
dir = 0;
cur = pre;
}
s.erase(lef);
} else if(dif1 > dif2) {
if(cur != nxt) {
dir = 1;
cur = nxt;
}
s.erase(rig);
} else {
if(dir) cur = nxt, s.erase(rig);
else cur = pre, s.erase(lef);
}
}
}
printf("Case %d: %I64d\n", ++kase, ans);
}
return 0;
}
2. 赛后写的更加优美的代码 这种不用纠结特判相等会隐藏的修改了方向
//
// Created by TaoSama on 2015-09-12
// Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>
using namespace std;
#define pr(x) cout << #x << " = " << x << " "
#define prln(x) cout << #x << " = " << x << endl
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;
int n, q;
int main() {
#ifdef LOCAL
freopen("in.txt", "r", stdin);
// freopen("out.txt","w",stdout);
#endif
ios_base::sync_with_stdio(0);
int t; scanf("%d", &t);
int kase = 0;
while(t--) {
scanf("%d%d", &n, &q);
multiset<int> s;
multiset<int>::iterator iter;
int cur = 0, dir = 1;
long long ans = 0;
while(q--) {
// printf("q: %d\n", q);
int op, x; scanf("%d", &op);
if(op == 0) {
scanf("%d", &x);
s.insert(x);
} else {
if(s.size() == 0) continue;
iter = s.lower_bound(cur);
if(iter == s.end()) x = *(--iter);
else if(iter == s.begin()) x = *iter;
else {
int r = *iter, l = *(--iter);
if(cur - l > r - cur) x = r;
else if(cur - l < r - cur) x = l;
else x = dir ? r : l;
}
if(x > cur) dir = 1;
else if(x < cur) dir = 0;
ans += abs(x - cur);
cur = x;
s.erase(s.find(x));
}
}
printf("Case %d: %I64d\n", ++kase, ans);
}
return 0;
}