老年人康复计划

1.搜索

先从最简单的dfs开始吧

洛谷1019单词接龙

瞎dfs即可

#include 
#include <string>
#include 
#include 
using namespace std;
int n, ans;
string s[21];
int vis[21];

void dfs(int a, int len) {
    if (vis[a] == 2)    return;
    ans = max(len, ans);
    vis[a]++;
    for (int i = 0; i < s[a].size(); i++)
        for (int j = 1; j <= n; j++) {
            if (i == 0 && a != 0)    break;
            int l = i, r = 0;
            while(s[a][l] == s[j][r])
                l++, r++;
            if (l == s[a].size())    dfs(j, len + s[j].size() - (s[a].size() - i));
        }
    vis[a]--;        
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
        cin >> s[i];
    cin >> s[0];
    dfs(0, 1);
    printf("%d", ans);
    return 0;
}

一遍AC，感觉不错

 

2.bfs

luogu1443马的遍历

裸bfs题，但由于我太菜做了很久很久（真就癌症晚期

说一下我遇到的问题吧

1.忘了pop，然后就绝望tle，听到电脑风扇嗡嗡翁的响

2.是八种走路方法，不是四种

3.vis请在push的时候一起标记，不然就会出现同一个东西被丢进去一万次的尴尬局面，就会快乐tle

4.最后就是宽五格的问题，我最开始以为是printf("%d    ", a)这种方法，发现自己WA的之后才知道需要printf("%-5d", a);

tip：%-md：输出格式为整形，长度为m(输出最小长度)，左对齐；可用m表示你的3，4，5，121；

#include 
#include 
#include 
#include 
using namespace std;
int n, m, x, y;
const int N = 510;
#define mp(a, b, c) make_pair(a, make_pair(b, c))
#define f first
#define s second
typedef pair <int, pair<int, int> > P;
queue < P > Q;
int move[8][2] = {{2, 1}, {2, -1}, {-2, 1}, {-2, -1}, {1, 2}, {1, -2}, {-1, 2}, {-1, -2}};
int ans[N][N];
bool vis[N][N];

int main() {
    scanf("%d %d %d %d", &n, &m, &x, &y);
    Q.push(mp(0, x - 1, y - 1));
    memset(ans, 0xffffffff, sizeof(ans));
    vis[x - 1][y - 1] = true;
    while (!Q.empty()) {
        int a = Q.front().s.f;
        int b = Q.front().s.s;
        int step = Q.front().f; Q.pop();
        ans[a][b] = step;
        for (int i = 0; i < 8; i++) {
            int mx = a + move[i][0];
            int my = b + move[i][1];
            if (mx >= n || mx < 0)    continue;
            if (my >= m || my < 0)    continue;
            if (!vis[mx][my]) {
                vis[mx][my] = true;
                Q.push(mp(step + 1, mx, my));
            }
        }
    }
    for (int i = 0; i < n; i++) {    
        for (int j = 0; j < m; j++)
            printf("%-5d", ans[i][j]);
        puts("");
    }
    return 0;
}

3.再来一次bfs吧

luogu1162填涂颜色

找联通块即可

#include 
#include 
using namespace std;
const int N = 32;
int map[N][N];
bool vis[N][N];
typedef pair <int, int> P;
#define f first
#define s second
queue < P > Q;
int move[4][2] {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int main() {
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) {
            scanf("%d", &map[i][j]);
            if (map[i][j])    vis[i][j] = true;
        }
    for (int i = 0; i < n; i++) {
        if (!map[i][0])    Q.push(make_pair(i, 0)), vis[i][0] = true;
        if (!map[i][n - 1])    Q.push(make_pair(i, n - 1)), vis[i][n - 1] = true;
    }
    for (int i = 1; i < n - 1; i++) {
        if (!map[0][i])    Q.push(make_pair(0, i)), vis[0][i] = true;
        if (!map[n - 1][i])    Q.push(make_pair(n - 1, i)), vis[n - 1][i] = true;
    }
    while (!Q.empty()) {
        P u = Q.front();
        Q.pop();
        for (int i = 0; i < 4; i++) {
            int mx = u.f + move[i][0];
            int my = u.s + move[i][1];
            if (mx >= n || mx < 0 || my >= n || my < 0)    continue;
            if (!vis[mx][my]) {
                vis[mx][my] = 1;
                Q.push(make_pair(mx, my));
            }
        }
    }
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (!vis[i][j])    map[i][j] = 2;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            printf("%d ", map[i][j]);
        puts("");
    }
    return 0;
}

 

转载于:https://www.cnblogs.com/cminus/p/11601064.html