[csu1603] Greed

Test instructions: There are n examination, for examination I, do not review it can test Si, review it can improve AI points per hour, every hour AI will reduce Di, that is, the continuous review of an account of an increase in the hours of the AI, Ai-di, Ai-2di ..., but the highest score of each exam is not more than 100 points, Given the test time of each exam, and the exam itself does not occupy the time, reasonable arrangement review plan, ask whether to let all exams are not less than 60 points, if possible, the total maximum is how much.

Ideas: More obvious greed, but it is difficult to think of the right greedy strategy. We divide the problem into two steps, all of which pass 60 points and the total score is the largest. For the first step, for not review scores less than 60 points of the subject, first review for a period of time to score 60 points, greedy from the test time to extend to find free time to review (once can not find free time, then no solution). For the second step, chronological order of the processing, for a time t, enumerate all the test time is greater than or equal to T of the account, find an account, so that review it to improve the highest score, then time t is used to review the course.

1 #pragmaComment (linker, "/stack:10240000,10240000")2 3#include <iostream>4#include <cstdio>5#include <algorithm>6#include <cstdlib>7#include <cstring>8#include <map>9#include <queue>Ten#include <deque> One#include <cmath> A#include <vector> -#include <ctime> -#include <cctype> the#include <Set> -#include <bitset> -#include <functional> -#include <numeric> +#include <stdexcept> -#include <utility> +  A using namespacestd; at  - #defineMem0 (a) memset (a, 0, sizeof (a)) - #defineMem_1 (a) memset (a,-1, sizeof (a)) - #defineLson L, M, RT << 1 - #defineRson m + 1, R, RT << 1 | 1 - #definedefine_m int m = (L + r) >> 1 in #defineRep_up0 (A, b) for (int a = 0; a < (b); a++) - #defineRep_up1 (A, b) for (int a = 1; a <= (b); a++) to #defineRep_down0 (A, b) for (int a = b-1; a >= 0; a--) + #defineRep_down1 (A, b) for (int a = b; a > 0; a--) - #defineAll (a) (a). Begin (), (a). End () the #defineLowbit (x) ((x) & (-(x))) * #defineCONSTRUCTINT4 (name, a, B, C, D) name (int a = 0, int b = 0, int c = 0, int d = 0): A (a), B (b), C (c), D (d) {} $ #defineCONSTRUCTINT3 (name, a, B, c) name (int a = 0, int b = 0, int c = 0): A (a), B (b), C (c) {}Panax Notoginseng #defineConstructInt2 (name, a, b) name (int a = 0, int b = 0): A (a), B (b) {} - #definePCHR (a) Putchar (a) the #definePstr (a) printf ("%s", a) + #defineSstr (a) scanf ("%s", a) A #defineSint (a) scanf ("%d", &a) the #defineSint2 (A, b) scanf ("%d%d", &a, &b) + #defineSint3 (A, B, c) scanf ("%d%d%d", &a, &b, &c) - #definePint (a) printf ("%d\n", a) $ #defineTest_print1 (a) cout << "var1 =" << a << Endl $ #defineTest_print2 (A, b) cout << "var1 =" << a << ", var2 =" << b << Endl - #defineTest_print3 (A, B, c) cout << "var1 =" << a << ", var2 =" << b << ", Var3 =" << c &L t;< Endl -  thetypedefLong LongLL; -typedef pair<int,int>PII;Wuyitypedef vector<int>VI; the  - Const intdx[8] = {0,0, -1,1,1,1, -1, -1}; Wu Const intdy[8] = {-1,1,0,0,1, -1,1, -1 }; - Const intMAXN = 3e4 +7; About Const intMD =10007; $ Const intINF = 1e9 +7; - ConstLL inf_l = 1e18 +7; - Const DoublePI = ACOs (-1.0); - Const DoubleEPS = 1e-4; A  +template<classT>t gcd (t A, T b) {returnb==0? A:GCD (b,a%b);} thetemplate<classT>BOOLMax_update (T &a,ConstT &b) {if(B>a) {a = B;return true;}return false;} -template<classT>BOOLMin_update (T &a,ConstT &b) {if(B<a) {a = B;return true;}return false;} $template<classT>t condition (BOOLF, t A, T b) {returnF?a:b;} thetemplate<classT>voidCopy_arr (t a[], T b[],intN) {rep_up0 (i,n) a[i]=b[i];} the intMAKE_ID (intXintYintN) {returnX * n +y;} the  the structNode { -     intR, S, a, D; inNode (intR =0,ints =0,intA =0,intD =0): R (R), s (s), A (a), D (d) {} the     BOOL operator< (ConstNode that)Const { the         returnR <THAT.R; About     } the }; theNode node[ -]; the BOOLocc[ +]; +  - intMain () { the     //freopen ("In.txt", "R", stdin);Bayi     intN; the      while(Cin >>N) { the         intMaxt =0; -         BOOLOK =true; - mem0 (OCC); the rep_up0 (i, n) { the             intS, T, a, d, tmp =0; theCIN >> s >> T >> a >>D; theNode[i] =Node (t, S, a, d); - max_update (Maxt, t); the         } theSort (node, node +n); the rep_up0 (i, n) {94             intCur =NODE[I].R; the              while(Node[i].s < -) { the                  while(Occ[cur] && cur) cur--; the                 if(!cur | | node[i].a <=0) {98OK =false; About                      Break; -                 }101Occ[cur] =true;102Node[i].s + =node[i].a;103NODE[I].A-=node[i].d;104             } the             if(!ok) Break;106         }107 rep_down1 (i, maxt) {108             if(!Occ[i]) {109                 ints =0, p; the Rep_up0 (j, N) {111                     if(NODE[J].R >=i) { the                         intDAT =node[j].a;113                         if(Node[j].s + dat > -) dat = --Node[j].s; the                         if(Dat >s) { thes =dat; thep =J;117                         }118                     }119                 } -                 if(s) {121Node[p].s + =s;122NODE[P].A-=node[p].d;123                 }124             } the         }126         intAns =0;127 rep_up0 (i, n) { -Ans + =Node[i].s;129         } the         if(OK) cout << ans <<Endl;131         ElsePuts"You are unlucky"); the     }133}

View Code

[csu1603] Greed