BUN 34981 A Matrix

每次从第一行选一个数，向下找递增的一条链。。。

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

const int maxn = 100005;

vector<int> vec[maxn];
int cnt[maxn];
int res[maxn], ans, n, m;

void solve(int pos, int t)
{
	if(pos == m || cnt[pos+1] == 0 || vec[pos+1][cnt[pos+1]-1] < vec[pos][t]) return;
	res[ans++] = vec[pos+1][cnt[pos+1]-1];
	cnt[pos+1]--;
	solve(pos+1, cnt[pos+1]);
}

void work()
{
	scanf("%d%d", &n, &m);
	
	int ok = 1;
	for(int i = 1; i <= n; i++) vec[i].clear();
	for(int i = 1; i <= m; i++) {
		scanf("%d", &cnt[i]);
		for(int j = 0; j < cnt[i]; j++) {
			int x;
			scanf("%d", &x);
			if(j && x < vec[i][j-1]) ok = 0;
			vec[i].push_back(x);
		}
	}

	if(!ok) {
		printf("No solution\n");
		return;
	}

	ans = 0;
	for(int i = vec[1].size()-1; i >= 0; i--) {
		res[ans++] = vec[1][i];
		solve(1, i);
	}

	if(ans != n) printf("No solution\n");
	else {
		for(int i = ans - 1; i >= 0; i--) printf("%d%c", res[i], i ? ' ' : '\n');
	}
	
}

int main()
{
	int _;
	scanf("%d", &_);
	for(int i = 1; i <= _; i++) {
		printf("Case #%d: ", i);
		work();
	}
	
	return 0;
}