hdu,1051,Wooden Sticks

#include<stdio.h>#include<string.h>#include<algorithm>using namespace std;struct stick{int l, weight;int flag;}a[5010];int cmp(stick a, stick b){if(a.l != b.l) return a.l < b.l;else return a.weight < b.weight;}int main(){int t, n;scanf("%d", &t);while(t--){scanf("%d", &n);for(int i = 0; i < n; i++){scanf("%d%d", &a[i].l, &a[i].weight);a[i].flag = 0;}sort(a, a+n, cmp);int num = 1;int ans = 0;int st = 0;  //st保留前一个花时间的木棍 while(num != n){  //遍历的总数 for(int i = 1; i < n; i++){if(a[i].weight >= a[st].weight && a[i].flag == 0){num++;st = i;  a[i].flag = 1;}}ans++;//每遍历完一遍，需要花费时间的木棍数加1 for(int i = 1; i < n; i++){if(a[i].flag == 0){st = i;break;}}}printf("%d\n", ans);}return 0;}//个人觉得下面的更好 少用一个循环 #include<stdio.h>#include<string.h>#include<algorithm>using namespace std;struct stick{    int l;    int w;    int dis;}a[5020];int cmp(stick a1, stick a2){    if(a1.l < a2.l) return 1;    else if(a1.l == a2.l) return a1.w < a2.w;    return 0;}int main(){    int n, m, i, j;    scanf("%d", &n);    while(n--){        memset(a, 0, sizeof(a));        scanf("%d", &m);        for(i = 0; i < m; i++){            scanf("%d%d", &a[i].l, &a[i].w);            a[i].dis = 0;        }        sort(a, a+m, cmp);        int sum = 0, v;        for(i = 0; i < m; i++){  //依次判断每个木棍有没有被用过，也用来表示每次遍历的第一个             if(a[i].dis == 0){                sum++;                a[i].dis = 1;                v = a[i].w;                for(j = i+1; j < m; j++){                    if(v <= a[j].w && a[j].dis == 0){                        a[j].dis = 1;                        v = a[j].w;                    }                }            }        }        printf("%d\n", sum);    }    return 0;}

Wooden Sticks

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 22328    Accepted Submission(s): 8990

Problem Description

There is a pile of n wooden sticks. The length and weight of each stick are known in advance. The sticks are to be processed by a woodworking machine in one by one fashion. It needs some time, called setup time, for the machine to prepare processing a stick. The setup times are associated with cleaning operations and changing tools and shapes in the machine. The setup times of the woodworking machine are given as follows:

(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.

 

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

213