UVa 103 Stacking Boxes

/*
Author: ACboy
Date: 2010-5-19
Result: AC
Descripition: UVa 103 Stacking Boxes
*/
#include <iostream>
#include <algorithm>
using namespace std;

//邻接矩阵
int g[40][40];
//记录每条边
int edg[35][15];
//dp数组
int d[40];
//用来保存结果
int res[40];

//最长的路径的长度
int c;
int k, n;

int if_edg(int a, int b) {
int i;
int ok = 1;
for (i = 1; i <= n; i++) {
if (edg[a][i] >= edg[b][i]) {
ok = 0;
break;
}
}
return ok;
}

// 记忆化搜索（DP）
int dp(int i) {
int &ans = d[i];
if (ans > 0) {
return ans;
}
ans = 1;
for (int j = 1; j <= k; j++) {
if (g[i][j]) {
if (dp(j) + 1 > ans) {
ans = dp(j) + 1;
}
}
}
return ans;
}

// 根据d[]计算出结果并保存在res中。
void find_ans(int i) {
res[c++] = i;
for (int j = 1; j <= k; j++) {
if (g[i][j] && d[i] == d[j] + 1) {
find_ans(j);
break;
}
}
}

int main() {
#ifndef ONLINE_JUDGE
freopen("103.txt", "r", stdin);
#endif
while (cin >> k >> n) {
int i, j;
for (i = 1; i <= k; i++) {
for (j = 1; j <= n; j++) {
cin >> edg[i][j];
}
sort(edg[i] + 1, edg[i] + n + 1);
}
memset(g, 0, sizeof(g));
for (i = 1; i <= k; i++) {
for (j = 1; j <= k; j++) {
if (if_edg(i, j)) {
g[i][j] = 1;
}
}
}
memset(d, 0, sizeof(d));
for (i = 1; i <= k; i++) {
dp(i);
}
int max = -1;
int pos = -1;
for (i = 1; i <= k; i++) {
if (d[i] > max) {
max = d[i];
pos = i;
}
}
cout << max << endl;
c = 0;
find_ans(pos);
for (i = 0; i < c - 1; i++) {
cout << res[i] << " ";
}
cout << res[c - 1] << endl;
}
return 0;
}