CSU 1352: New Sorting Algorithm 1355: 地雷清除计划 1356: Catch

1352: New Sorting Algorithm

#include<cstdio>
#include<algorithm>
#define maxn 100005
using namespace std;
int n,t,m;
int num[maxn],f[maxn],r[maxn],cnt[maxn];
 
bool cmp(const int &x,const int &y)
{
    return num[x]<num[y];
}
 
int find(int x)
{
    return f[x]==x?x:f[x]=find(f[x]);
}
 
void merge(int x,int y)
{
    int xx=find(x);
    int yy=find(y);
    if(xx!=yy)f[yy]=xx,cnt[xx]+=cnt[yy];
}
 
void pre()
{
    for(int i=1; i<=n; i++)r[i]=i;
    sort(r+1,r+n+1,cmp);
    for(int i=1; i<=n; i++)num[r[i]]=i;
    for(int i=1; i<=n; i++)f[i]=i,cnt[i]=1;
}
 
void solve()
{
    long long ans=0;
    bool flag=1;
    for(int i=r[1]; i<n; i++)
        if(num[i]>num[i+1])
        {
            flag=0;
            break;
        }
    if(flag)m=r[1]-1;
    else m=n;
    for(int i=1; i<=m; i++)
    {
        int v=num[i];
        ans+=cnt[v];
        merge(v-1,v);
    }
    printf("%lld\n",ans);
}
 
int main()
{
//    freopen("test0.in","r",stdin);
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        for(int i=1; i<=n; i++)
            scanf("%d",&num[i]);
        pre();
        solve();
    }
    return 0;
}
/**********************************************************************
	Problem: 1352
	User: 3901140225
	Language: C++
	Result: AC
	Time:160 ms
	Memory:2680 kb
**********************************************************************/

1355: 地雷清除计划


#include <map>
#include <set>
#include <cmath>
#include <ctime>
#include <stack>
#include <queue>
#include <cstdio>
#include <cctype>
#include <bitset>
#include <string>
#include <vector>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <functional>
#define fuck(x) cout<<"["<<x<<"]";
#define FIN freopen("input.txt","r",stdin);
#define FOUT freopen("output.txt","w+",stdout);
//#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
typedef long long LL;
typedef pair<int, int>PII;

const int MX = 1e3;
const int MS = 4e5 + 5;
const int INF = 0x3f3f3f3f;

template<class T>
struct Max_Flow {
    int n;
    int Q[MX], sign;
    int head[MX], level[MX], cur[MX], pre[MX];
    int nxt[MS], pnt[MS], E;
    T cap[MS];
    void Init(int n) {
        E = 0;
        this->n = n + 1;
        fill(head, head + this->n, -1);
    }
    void Add(int from, int to, T c, T rw = 0) {
        pnt[E] = to; cap[E] = c; nxt[E] = head[from]; head[from] = E++;
        pnt[E] = from; cap[E] = rw; nxt[E] = head[to]; head[to] = E++;
    }
    bool BFS(int s, int t) {
        sign = t;
        std::fill(level, level + n, -1);
        int *front = Q, *tail = Q;
        *tail++ = t; level[t] = 0;
        while (front < tail && level[s] == -1) {
            int u = *front++;
            for (int e = head[u]; e != -1; e = nxt[e]) {
                if (cap[e ^ 1] > 0 && level[pnt[e]] < 0) {
                    level[pnt[e]] = level[u] + 1;
                    *tail++ = pnt[e];
                }
            }
        }
        return level[s] != -1;
    }
    void Push(int t, T &flow) {
        T mi = INF;
        int p = pre[t];
        for (int p = pre[t]; p != -1; p = pre[pnt[p ^ 1]]) {
            mi = std::min(mi, cap[p]);
        }
        for (int p = pre[t]; p != -1; p = pre[pnt[p ^ 1]]) {
            cap[p] -= mi;
            if (!cap[p]) {
                sign = pnt[p ^ 1];
            }
            cap[p ^ 1] += mi;
        }
        flow += mi;
    }
    void DFS(int u, int t, T &flow) {
        if (u == t) {
            Push(t, flow);
            return;
        }
        for (int &e = cur[u]; e != -1; e = nxt[e]) {
            if (cap[e] > 0 && level[u] - 1 == level[pnt[e]]) {
                pre[pnt[e]] = e;
                DFS(pnt[e], t, flow);
                if (level[sign] > level[u]) {
                    return;
                }
                sign = t;
            }
        }
    }
    T Dinic(int s, int t) {
        pre[s] = -1;
        T flow = 0;
        while (BFS(s, t)) {
            std::copy(head, head + n, cur);
            DFS(s, t, flow);
        }
        return flow;
    }
};
Max_Flow<int>F;

char s[MX];
int T, n, m, k;
PII P[MX]; int tot;
int dist(PII a, PII b) {
    return abs(a.first - b.first) + abs(a.second - b.second);
}
inline bool check(PII a, PII b, int k) {
    if((a.first == b.first || a.second == b.second) && dist(a, b) <= 2 * k + 1) return 1;
    if((a.first != b.first && a.second != b.second) && dist(a, b) <= 2 * k + 2) return 1;
    return 0;
}
int main() {
    //FIN;
    scanf("%d", &T);
    while(T--) {
        tot = 0;
        scanf("%d%d%d", &n, &m, &k);

        for(int i = 1; i <= n; i++) {
            scanf("%s", s + 1);
            for(int j = 1; j <= m; j++) {
                if(s[j] == '*') P[++tot] = PII(i, j);
            }
        }

        int s = 0, t = 2 * tot + 1;
        F.Init(t + 1);
        for(int i = 1; i <= tot; i++) {
            F.Add(i, i + tot, 1);
            if(P[i].first + k >= n || P[i].second - k <= 1) {
                F.Add(s, i, INF);
            }
            if(P[i].first - k <= 1 || P[i].second + k >= m) {
                F.Add(i + tot, t, INF);
            }
            for(int j = i + 1; j <= tot; j++) {
                if(check(P[i], P[j], k)) {
                    F.Add(i + tot, j, INF);
                    F.Add(j + tot, i, INF);
                }
            }
        }
        printf("%d\n", F.Dinic(s, t));
    }
    return 0;
}
/**********************************************************************
	Problem: 1355
	User: 3901140225
	Language: C++
	Result: AC
	Time:116 ms
	Memory:6744 kb
**********************************************************************/


1356: Catch


#include <cstdio>
#include <ctime>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <string>
#include <set>
#include <stack>
#include <map>
#include <cmath>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

typedef long long LL;
const int INF = 1000000007;
const double eps = 1e-10;
const int maxn = 100010;
const int MOD = 9997;

int n;
int m, st;
int tot;
vector<int>adj[maxn];
int vis[maxn];
int fla;

int dfs(int x, int fa, int val)
{
    if (vis[x] == -1) vis[x] = val;
    else return vis[x];
    tot++;

    for (int i = 0; i < adj[x].size(); i++)
    {
        int y = adj[x][i];
        //if (y != fa)
        //{
            if (vis[x] == dfs(y, x, vis[x] ^ 1))
                fla = 1;
        //}
    }
    return vis[x];
}

int main ()
{
    int T;
    cin >> T;
    int x, y;
    int ncase = 1;
    while (T--)
    {
        memset(vis, -1, sizeof(vis));///初始化为-1,染成0和1
        cin >> n >> m >> st;
        for (int i = 0; i< n; i++) adj[i].clear();
        while (m--)
        {
            scanf("%d%d", &x,&y);
            adj[x].push_back(y);
            adj[y].push_back(x);
        }
        fla = 0;///判断是否找到奇环
        tot = 0;///记录联通的点数
        dfs(st, -1, 0);

        printf("Case %d: ", ncase++);
        if (fla && tot == n) puts("YES");
        else puts("NO");
    }

    return 0;
}


/**********************************************************************
	Problem: 1356
	User: 3901140225
	Language: C++
	Result: AC
	Time:316 ms
	Memory:7368 kb
**********************************************************************/

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