經典DP 嵌套矩形

    dp初級入門必學，有南陽理工學院OJ的題在此：http://acm.nyist.net/JudgeOnline/problem.php?pid=16

    簡單dp，劉汝佳白書第一本，161頁。稍微理解下就會了。。很easy

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;#define max(a,b)((a)>(b)?(a):(b))#define min(a,b)((a)<(b)?(a):(b))const int maxn = 15;struct Node{int x, y;}node[maxn];int cmp(Node a, Node b){if (a.y == b.y)return a.x > b.x;return a.y > b.y;}int main(){int N;int dp[maxn];scanf("%d", &N);while (N--){int n;scanf("%d", &n);int i, j;for (i=0; i<n; i++){int tmpa, tmpb;scanf("%d %d", &tmpa, &tmpb);node[i].x = min(tmpa, tmpb);node[i].y = max(tmpa, tmpb);}sort(node, node+n, cmp);for (i=n-1; i>=0; i--){dp[i] = 1;for (j=n-1; j>i; j--){if (node[j].x < node[i].x && node[j].y <=node[i].y)if (dp[i] < dp[j] + 1)dp[i] = dp[j] + 1;}}int max = 0;for (i=0; i<n; i++)if (dp[i] > max)max = dp[i];printf("%d\n", max);}return 0;}