HDU 1051 Wooden Sticks 貪心||DP
阿新 • • 發佈:2017-07-12
scanf rep code 子列 iss miss minimum span mission
(a) The setup time for the first wooden stick is 1 minute.
(b) Right after processing a stick of length l and weight w , the machine will need no setup time for a stick of length l‘ and weight w‘ if l<=l‘ and w<=w‘. Otherwise, it will need 1 minute for setup.
You are to find the minimum setup time to process a given pile of n wooden sticks. For example, if you have five sticks whose pairs of length and weight are (4,9), (5,2), (2,1), (3,5), and (1,4), then the minimum setup time should be 2 minutes since there is a sequence of pairs (1,4), (3,5), (4,9), (2,1), (5,2).
Input
The input consists of T test cases. The number of test cases (T) is given in the first line of the input file. Each test case consists of two lines: The first line has an integer n , 1<=n<=5000, that represents the number of wooden sticks in the test case, and the second line contains n 2 positive integers l1, w1, l2, w2, ..., ln, wn, each of magnitude at most 10000 , where li and wi are the length and weight of the i th wooden stick, respectively. The 2n integers are delimited by one or more spaces.
Output
The output should contain the minimum setup time in minutes, one per line.
Wooden Sticks
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 22000 Accepted Submission(s): 8851
(a) The setup time for the first wooden stick is 1 minute.
(b) Right after processing a stick of length l and weight w , the machine will need no setup time for a stick of length l‘ and weight w‘ if l<=l‘ and w<=w‘. Otherwise, it will need 1 minute for setup.
You are to find the minimum setup time to process a given pile of n wooden sticks. For example, if you have five sticks whose pairs of length and weight are (4,9), (5,2), (2,1), (3,5), and (1,4), then the minimum setup time should be 2 minutes since there is a sequence of pairs (1,4), (3,5), (4,9), (2,1), (5,2).
Sample Input 3 5 4 9 5 2 2 1 3 5 1 4 3 2 2 1 1 2 2 3 1 3 2 2 3 1
Sample Output 2 1 3
Source Asia 2001, Taejon (South Korea) 思路:將木棒按l,w 遞減的順序排列,統計關於遞減的連續子列的個數即為答案。 代碼:
1 #include "cstdio" 2#include "iostream" 3 #include "algorithm" 4 #include "string" 5 #include "cstring" 6 #include "queue" 7 #include "cmath" 8 #include "vector" 9 #include "map" 10 #include "stdlib.h" 11 #include "set" 12 #define mj 13 #define db double 14 #define ll long long 15 using namespace std; 16 const int N=1e6+5; 17 const int mod=1e9+7; 18 const ll inf=1e16+10; 19 bool u[N]; 20 typedef struct stu{ 21 int l,w; 22 }M; 23 M s[5005]; 24 int cmp(M a,M b) 25 { 26 if(a.l==b.l) return a.w>=b.w; 27 return a.l>=b.l; 28 } 29 int main() 30 { 31 int t,n,i,j,ans; 32 scanf("%d",&t); 33 while(t--) 34 { 35 scanf("%d",&n); 36 for(i=0;i<n;i++) 37 scanf("%d%d",&s[i].l,&s[i].w),u[i]=0; 38 sort(s,s+n,cmp); 39 int mi; 40 ans=0; 41 for(i=0;i<n;i++) 42 { 43 if(u[i]) continue; 44 mi=s[i].w; 45 for(j=i+1;j<n;j++) 46 { 47 if(!u[j]&&s[j].w<=mi){ 48 mi=s[j].w; 49 u[j]=1; 50 } 51 } 52 ans++; 53 } 54 printf("%d\n",ans); 55 } 56 return 0; 57 }
HDU 1051 Wooden Sticks 貪心||DP