【luogu P1514 引水入城】 题解

题目链接：https://www.luogu.org/problemnew/show/P1514

 // luogu-judger-enable-o2
 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 #define maxn 520
 #define inf 2147483647
 using namespace std;
 int n, m, cnt = , cur1 = , flag, ma[maxn][maxn], vis[maxn][maxn] = {}, q[maxn];
 struct cover
 {
     int l,r;
 }c[maxn];
 int cmp(cover a, cover b)
 {
     if(a.l != b.l)
     return a.l < b.l;
     else return a.r > b.r;
 }
 void dfs(int x, int y, int now)
 {
     vis[x][y] = ;
     if(x == n)
     {
         q[y] = ;
         c[now].l = min(c[now].l , y);
         c[now].r = max(c[now].r , y);
     }

     if(ma[x+][y] < ma[x][y] && x+ <= n && vis[x+][y] == ) dfs(x+,y,now);

     if(ma[x-][y] < ma[x][y] && x- >=  && vis[x-][y] == ) dfs(x-,y,now); 

     if(ma[x][y+] < ma[x][y] && y+ <= m && vis[x][y+] == ) dfs(x,y+,now);

     if(ma[x][y-] < ma[x][y] && y- >=  && vis[x][y-] == ) dfs(x,y-,now);
 }
 int main()
 {
     scanf("%d%d",&n,&m);
     for(int i = ; i <= m; i++)
     c[i].l = inf;

     for(int i = ; i <= n; i++)
     for(int j = ; j <= m; j++)
     {
         scanf("%d",&ma[i][j]);
     }

     for(int i = ; i <= m; i++)
     {
         if(ma[][i]>=ma[][i-])
         dfs(,i,i);
         memset(vis,,sizeof(vis));
     }

     for(int i=;i<=m;i++)
     {
         if(q[i] == )
         flag++;
         //cout<<q[i]<<" ";
     }

     sort(c+,c++m,cmp);

     if(flag != )
     printf("0\n%d",flag);
     else
     {
         int cur = c[].r;
         cnt++;
         for(int i = cur; i <= m; i = cur1)
         {
             if(i == m)
             break;

             cnt++;

             for(int j = ; c[j].l <= i+; j++)
             cur1 = max(cur1, c[j].r);
         }
         printf("1\n%d",cnt);
     }
     return ;
 }