比赛 |
2025暑期集训第8场 |
评测结果 |
AAAAAA |
题目名称 |
狼抓兔子 |
最终得分 |
100 |
用户昵称 |
淮淮清子 |
运行时间 |
0.640 s |
代码语言 |
C++ |
内存使用 |
15.45 MiB |
提交时间 |
2025-08-13 11:49:17 |
显示代码纯文本
#include <iostream>
#include <queue>
#include <cstring>
using namespace std;
#define val(i, j) ((i - 1) * m + j)
const int MAXN = 1005, MAXM = 6e6 + 10;
int h[MAXN * MAXN], cnt[MAXN * MAXN], d[MAXN * MAXN], tot = 1;
int n, m, S, T, ans;
struct node{
int to, next, w;
}e[MAXM];
void add(int u, int v, int w){
e[++ tot] = {v, h[u], w};
h[u] = tot;
e[++ tot] = {u, h[v], w};
h[v] = tot;
}
bool bfs(){
memset(d, 0, sizeof d);
queue<int> q;
q.push(S); d[S] = 1;
while(!q.empty()){
int u = q.front(); q.pop();
for(int i = h[u];i;i = e[i].next){
int v = e[i].to;
if(!d[v] && e[i].w){
d[v] = d[u] + 1;
if(v == T) return true;
q.push(v);
}
}
}
return false;
}
int dfs(int u, int flow){
if(u == T) return flow;
int res = 0;
for(int i = cnt[u];i;i = e[i].next){
int v = e[i].to;
if((d[v] == d[u] + 1) && e[i].w){
int k = dfs(v, min(flow - res, e[i].w));
if(!k) d[v] = 0;
e[i].w -= k;
e[i ^ 1].w += k;
res += k;
if(res == flow) break;
}
}
return res;
}
int main(){
freopen("bjrabbit.in","r",stdin);
freopen("bjrabbit.out","w",stdout);
cin.tie(0) -> ios::sync_with_stdio(0);
cin >> n >> m;
S = val(1,1), T = val(n,m);
for(int i = 1, w;i <= n;i ++){
for(int j = 1;j < m;j ++){
cin >> w;
int u = val(i, j), v = val(i, j + 1);
add(u, v, w);
}
}
for(int i = 1, w;i < n;i ++){
for(int j = 1;j <= m;j ++){
cin >> w;
int u = val(i, j), v = val(i + 1, j);
add(u, v, w);
}
}
for(int i = 1, w;i < n;i ++){
for(int j = 1;j < m;j ++){
cin >> w;
int u = val(i, j), v = val(i + 1,j + 1);
add(u, v, w);
}
}
while(bfs()){
memcpy(cnt, h, sizeof h);
ans += dfs(S, 1e9);
}
cout << ans << '\n';
return 0;
}