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HDU - 1074 Doing Homework 狀壓DP

HDU - 1074

題意:

  有n份作業,每份作業都有截止日期和完成這份作業的時間。超過截止日期一天多扣一分。問如何安排作業可以使的扣的分數最少。

思路:

  由於n比較小,所以可以用狀態壓縮dp,2的15次 = 32 768。如何利用狀態壓縮呢?是這樣的,每個數在二進位制中都有15位,如果某個位值為1,表示當前這個作業已經完成。為0,則表示這個作業還沒有做。所以假設當前狀態為j,那麼,dp【j】可以由比j少一個1的狀態i轉移過來。

//#pragma GCC optimize(3)
//#pragma comment(linker, "/STACK:102400000,102400000")  
//c++ // #pragma GCC diagnostic error "-std=c++11" // #pragma comment(linker, "/stack:200000000") // #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") // #pragma GCC optimize("-fdelete-null-pointer-checks,inline-functions-called-once,-funsafe-loop-optimizations,-fexpensive-optimizations,-foptimize-sibling-calls,-ftree-switch-conversion,-finline-small-functions,inline-small-functions,-frerun-cse-after-loop,-fhoist-adjacent-loads,-findirect-inlining,-freorder-functions,no-stack-protector,-fpartial-inlining,-fsched-interblock,-fcse-follow-jumps,-fcse-skip-blocks,-falign-functions,-fstrict-overflow,-fstrict-aliasing,-fschedule-insns2,-ftree-tail-merge,inline-functions,-fschedule-insns,-freorder-blocks,-fwhole-program,-funroll-loops,-fthread-jumps,-fcrossjumping,-fcaller-saves,-fdevirtualize,-falign-labels,-falign-loops,-falign-jumps,unroll-loops,-fsched-spec,-ffast-math,Ofast,inline,-fgcse,-fgcse-lm,-fipa-sra,-ftree-pre,-ftree-vrp,-fpeephole2",3)
#include <algorithm> #include <iterator> #include <iostream> #include <cstring> #include <cstdlib> #include <iomanip> #include <bitset> #include <cctype> #include <cstdio> #include <string> #include <vector> #include
<stack> #include <cmath> #include <queue> #include <list> #include <map> #include <set> #include <cassert> using namespace std; #define lson (l , mid , rt << 1) #define rson (mid + 1 , r , rt << 1 | 1) #define debug(x) cerr << #x << " = " << x << "\n"; #define pb push_back #define pq priority_queue typedef long long ll; typedef unsigned long long ull; //typedef __int128 bll; typedef pair<ll ,ll > pll; typedef pair<int ,int > pii; typedef pair<int,pii> p3; //priority_queue<int> q;//這是一個大根堆q //priority_queue<int,vector<int>,greater<int> >q;//這是一個小根堆q #define fi first #define se second //#define endl '\n' #define OKC ios::sync_with_stdio(false);cin.tie(0) #define FT(A,B,C) for(int A=B;A <= C;++A) //用來壓行 #define REP(i , j , k) for(int i = j ; i < k ; ++i) #define max3(a,b,c) max(max(a,b), c); #define min3(a,b,c) min(min(a,b), c); //priority_queue<int ,vector<int>, greater<int> >que; const ll mos = 0x7FFFFFFF; //2147483647 const ll nmos = 0x80000000; //-2147483648 const int inf = 0x3f3f3f3f; const ll inff = 0x3f3f3f3f3f3f3f3f; //18 const int mod = 1e9+7; const double esp = 1e-8; const double PI=acos(-1.0); const double PHI=0.61803399; //黃金分割點 const double tPHI=0.38196601; template<typename T> inline T read(T&x){ x=0;int f=0;char ch=getchar(); while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar(); while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar(); return x=f?-x:x; } /*-----------------------showtime----------------------*/ struct node{ char str[200]; int d,c; }a[30]; const int maxn = 1e6+9; struct ode{ int time,pre,cost,fa; }dp[maxn]; int main(){ int n,T; scanf("%d", &T); while(T--){ scanf("%d", &n); for(int i=1; i<=n; i++) scanf("%s%d%d", a[i].str, &a[i].d, &a[i].c); memset(dp,0,sizeof(dp)); for(int j=1; j <(1<<n); j++){ dp[j].cost = inf; for(int i=n; i>=1; i--){ int tmp = (1 << (i-1)); if((tmp & j) > 0){ int pp = j - tmp; int fy = dp[pp].time + a[i].c - a[i].d; if(fy < 0) fy = 0; if(dp[j].cost > dp[pp].cost + fy){ dp[j].cost = dp[pp].cost + fy; dp[j].pre = i; dp[j].fa = pp; dp[j].time = dp[pp].time + a[i].c; } } } } int q = (1<<n) - 1; //debug(q); printf("%d\n", dp[q].cost); stack <int>tmp; while(q > 0){ tmp.push(dp[q].pre); q = dp[q].fa; } while(!tmp.empty()){ printf("%s\n", a[tmp.top()].str); tmp.pop(); } } return 0; }
HDU - 1074