1,单调队列;
(76条消息) 单调队列专题_Dull丶的博客-CSDN博客
2,kmp算法;
先是自己和自己匹配,求出ne数组,然后和另一串匹配,进行求解;
循环里三步:while,if,记录ne数组/挪串匹配;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e6+10,mod=1e6+3,base=131;
char s[N],p[N];
int ne[N];
int n,m;
signed main()
{quick_cin();cin>>n>>p+1>>m>>s+1;for(int i=2,j=0;i<=n;i++){while(j&&p[i]!=p[j+1])j=ne[j];if(p[i]==p[j+1])j++;ne[i]=j;}for(int i=1,j=0;i<=m;i++){while(j&&s[i]!=p[j+1])j=ne[j];if(s[i]==p[j+1])j++;if(j==n){cout<
3,trie树,最大异或和;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e6+10,mod=1e6+3,base=131;
int a[N],son[N<<2][2],idx;
int n;
void insert(int x)
{int p=0;per2(i,30,0){int s=x>>i&1;if(!son[p][s])son[p][s]=++idx;p=son[p][s];}
}
int search(int x)
{int p=0,res=0;per2(i,30,0){int s=x>>i&1;if(son[p][!s]){res+=1<>n;rep2(i,1,n){cin>>a[i];insert(a[i]);}int ans=0;rep2(i,1,n){ans=max(ans,search(a[i]));}dbug(ans);return 0;
}
4,n-皇后问题
对角线及反对角线的状态表示;
正对角线就是y+x,该线上y+x都一样
反对角线y-x都一样,但是数组下标不能为0,故统一加n;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e2+10,mod=1e6+3,base=131;
int n;
char g[N][N];
int col[N],dg[N],udg[N];
void dfs(int u)
{if(u==n){rep1(i,0,n)dbug(g[i]);cout<>n;rep1(i,0,n)rep1(j,0,n)g[i][j]='.';dfs(0);return 0;
}
5,走迷宫;
走到终点的最短路径,第一次走到的一定是最短的!因为是层向拓展,所以第一次走到的一定是最短的!;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e2+10,mod=1e6+3,base=131;
int n,m;
int a[N][N];
int d[N][N];
int dx[]={-1,0,1,0},dy[]={0,1,0,-1};
void bfs()
{queueq;q.push({1,1});d[1][1]=1;while(q.size()){auto t=q.front();q.pop();int x=t.first,y=t.second;rep1(i,0,4){int xx=x+dx[i];int yy=y+dy[i];if(xx>=1&&xx<=n&&yy>=1&&yy<=m&&!a[xx][yy]&&!d[xx][yy]){d[xx][yy]=d[x][y]+1;q.push({xx,yy});}}}dbug(d[n][m]-1);
}
signed main()
{quick_cin();cin>>n>>m;rep2(i,1,n)rep2(j,1,m)cin>>a[i][j];bfs();return 0;
}
6,dijkstra算法;
注意continue的使用;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e5+10,mod=1e6+3,base=131;
tulun;
void add(int a,int b,int c)
{w[idx]=c,e[idx]=b,ne[idx]=h[a],h[a]=idx++;
}
int n,m;
int dist[N];
int st[N];
void dijkstra()
{memset(dist,0x3f,dist);priority_queue,greater>q;q.push({0,1});dist[1]=0;while(q.size()){auto t=q.top();q.pop();int jl=t.first,ver=t.second;if(st[ver])continue;st[ver]=1;for(int i=h[ver];~i;i=ne[i]){int j=e[i];if(dist[j]>w[i]+jl){dist[j]=w[i]+jl;q.push({dist[j],j});}}}if(dist[n]==0x3f3f3f3f)dbug(-1);else dbug(dist[n]);
}
signed main()
{quick_cin();memset(h,-1,h);cin>>n>>m;rep2(i,1,m){int a,b,c;cin>>a>>b>>c;add(a,b,c);}dijkstra();return 0;
}
7,floyed算法;
适用数据范围小的最短路,可以求负权边;
注意初始化的方法,和dp类似,注意含义;
#pragma GCC optimize(3)
#include
#define rep1(i,a,n) for( int i=(a);i<(n);++i)
#define rep2(i,a,n) for( int i=(a);i<=(n);++i)
#define per1(i,n,a) for( int i=(n);i>(a);i--)
#define per2(i,n,a) for( int i=(n);i>=(a);i--)
#define quick_cin() cin.tie(0),cout.tie(0),ios::sync_with_stdio(false)
#define memset(a,i,b) memset((a),(i),sizeof (b))
#define memcpy(a,i,b) memcpy((a),(i),sizeof (b))
#define endl "\n"
#define lowbit(m) ((-m)&(m))
#define dbug(y) cout<<(y)<<"\n"
#define dbug2(a,b) cout<<(a)<<" "<<(b)<<"\n"
#define dbug3(a,b,c) cout<<(a)<<" "<<(b)<<" "<<(c)<<"\n"
#define dbug4(a,b,c,d) cout<<(a)<<" "<<(b)<<" "<<(c)<<" "<<(d)<<"\n"
#define tulun int e[N],ne[N],h[N],w[N],idx
#define T_solve() int T;cin>>T;while(T--)solve()
#define pi 3.14159265358979323846
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef pair PII;
typedef pair PLL;
typedef double dob;
const int N=1e3+10,mod=1e6+3,base=131;
int d[N][N];
int n,m,k;
#define inf 0x3f3f3f3f
void floyed()
{rep2(k,1,n)rep2(i,1,n)rep2(j,1,n)d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
}
signed main()
{quick_cin();cin>>n>>m>>k;rep2(i,1,n)rep2(j,1,m){if(i==j)d[i][j]=0;else d[i][j]=inf;}rep2(i,1,m){int a,b,c;cin>>a>>b>>c;d[a][b]=min(d[a][b],c);}floyed();rep2(i,1,k){int a,b;cin>>a>>b;if(d[a][b]>inf/2)dbug("impossible");else dbug(d[a][b]);}return 0;
}