week 1
AcWing104.货仓选址
#include <algorithm>
using namespace std;
const int N = 100010;
int n, res;
int a[N];
int main()
{
scanf("%d", &n);
for (int i = 0; i < n; i ++ ) scanf("%d", &a[i]);
sort(a, a + n);
for (int i = 0; i < n; i ++ ) res += abs(a[i] - a[n / 2]);
printf("%d\n", res);
return 0;
}
week 2
AcWing756.蛇形矩阵
#include<iostream>
using namespace std;
const int N = 110;
int n, m;
int q[N][N];
int main()
{
cin >> n >> m;
int dx[] = {
-1, 0, 1, 0}, dy[] = {
0, 1, 0, -1};
int x = 0, y = 0, d = 1;
for (int i = 1; i <= n * m; i ++)
{
q[x][y] = i;
int a = x + dx[d], b = y + dy[d];
if (a < 0 || a >= n || b < 0 || b >= m || q[a][b])
{
d = (d + 1) % 4;
a = x + dx[d], b = y + dy[d];
}
x = a, y = b;
}
for (int i = 0; i < n; i ++)
{
for (int j = 0; j < m; j ++)
cout << q[i][j] << ' ';
cout << endl;
}
return 0;
}
AcWing1113.红与黑
BFS
#include<iostream>
#include<queue>
#include<algorithm>
#define x first
#define y second
using namespace std;
typedef pair<int, int> PII;
const int N = 25;
int n, m;
char g[N][N];
int bfs(int sx, int sy)
{
queue<PII> q;
q.push({
sx, sy});
g[sx][sy] = '#';
int res = 0;
int dx[] = {
-1, 0, 1, 0}, dy[] = {
0, 1, 0, -1};
while (q.size())
{
auto t = q.front();
q.pop();
res ++ ;
for (int i = 0; i < 4; i ++)
{
int x = t.x + dx[i], y = t.y + dy[i];
if (x < 0 || x >= n || y < 0 || y >= m || g[x][y] != '.') continue;
q.push({
x, y});
g[x][y] = '#';
}
}
return res;
}
int main()
{
while(cin >> m >> n, n || m)
{
for (int i = 0; i < n; i ++) cin >> g[i];
int x, y;
for (int i = 0; i < n; i ++)
for (int j = 0; j < m; j ++)
if (g[i][j] == '@')
{
x = i;
y = j;
}
cout << bfs(x, y) << endl;
}
return 0;
}
DFS
#include<iostream>
using namespace std;
const int N = 25;
int n, m;
char g[N][N];
int dfs(int x, int y)
{
int res = 1;
g[x][y] = '#';
int dx[] = {
-1, 0, 1, 0}, dy[] = {
0, 1, 0, -1};
for (int i = 0; i < 4; i ++)
{
int a = x + dx[i], b = y + dy[i];
if (a < 0 || a >= n || b < 0 || b >= m || g[a][b] != '.') continue;
res += dfs(a, b);
}
return res;
}
int main()
{
while(cin >> m >> n, n || m)
{
for (int i = 0; i < n; i ++) cin >> g[i];
int x, y;
for (int i = 0; i < n; i ++)
for (int j = 0; j < m; j ++)
if (g[i][j] == '@')
{
x = i;
y = j;
}
cout << dfs(x