题目大意：有n个木棍，分别具有长度li和重量wi。对于木棍s1和s2，若l1<=l2且w1<=w2，则s1、s2可构成单调递增序列。求n个木棍中这样序列的个数。
最先的想法是，先排序，然后一遍一遍扫描，直到全部处理完。
1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 using namespace std; 5 #define MAXN 5000+10 6 7 struct Wooden 8 { 9 int l, w; 10 bool operator < (const Wooden& x) const 11 { 12 if (l != x.l) return l < x.l; 13 else return w < x.w; 14 } 15 }; 16 Wooden wooden[MAXN]; 17 bool processed[MAXN]; 18 19 int main() 20 { 21 #ifdef LOCAL 22 freopen("in", "r", stdin); 23 #endif 24 int T; 25 scanf("%d", &T); 26 while (T--) 27 { 28 int n; 29 scanf("%d", &n); 30 for (int i = 0; i < n; i++) 31 scanf("%d%d", &wooden[i].l, &wooden[i].w); 32 sort(wooden, wooden+n); 33 int time = 0; 34 memset(processed, 0, sizeof(processed)); 35 int remain = n; 36 while (remain > 0) 37 { 38 time++; 39 int prel = -1, prew = -1; 40 for (int i = 0; i < n; i++) 41 if (!processed[i] && wooden[i].l >= prel && wooden[i].w >= prew) 42 { 43 processed[i] = true; 44 remain--; 45 prel = wooden[i].l; 46 prew = wooden[i].w; 47 } 48 } 49 printf("%d ", time); 50 } 51 return 0; 52 }
看到网上说可以通过求解最长（严格）递减序列的答案，可是怎么都理解不了，留待以后吧...