今日SGU 5.12

SGU 149

题意：求每一个点的距离最远距离的点的长度

收获：次大值和最大值，dfs

#include<bits/stdc++.h>
#define de(x) cout<<#x<<"="<<x<<endl;
#define dd(x) cout<<#x<<"="<<x<<" ";
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define repd(i,a,b) for(int i=a;i>=(b);--i)
#define repp(i,a,b,t) for(int i=a;i<(b);i+=t)
#define ll long long
#define mt(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define pii pair<int,int>
#define pdd pair<double,double>
#define pdi pair<double,int>
#define mp(u,v) make_pair(u,v)
#define sz(a) (int)a.size()
#define ull unsigned long long
#define ll long long
#define pb push_back
#define PI acos(-1.0)
#define qc std::ios::sync_with_stdio(false)
#define db double
#define all(a) a.begin(),a.end()
const int mod = 1e9+;
const int maxn = 1e4+;
const double eps = 1e-;
using namespace std;
bool eq(const db &a, const db &b) { return fabs(a - b) < eps; }
bool ls(const db &a, const db &b) { return a + eps < b; }
bool le(const db &a, const db &b) { return eq(a, b) || ls(a, b); }
ll gcd(ll a,ll b) { return a==?b:gcd(b%a,a); };
ll lcm(ll a,ll b) { return a/gcd(a,b)*b; }
ll kpow(ll a,ll b) {ll res=;a%=mod; if(b<) return ; for(;b;b>>=){if(b&)res=res*a%mod;a=a*a%mod;}return res;}
ll read(){
    ll x=,f=;char ch=getchar();
    while (ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
    while (ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}
    return x*f;
}
//inv[1]=1;
//for(int i=2;i<=n;i++) inv[i]=(mod-mod/i)*inv[mod%i]%mod;
int mx[maxn][] = {};
vector<pii> G[maxn];
int dfs(int u,int p){
    rep(i,,sz(G[u])){
        int v=G[u][i].se,w=G[u][i].fi;
        if(v==p) continue;
        int tmp = dfs(v,u) + w;
        rep(i,,) if(mx[u][i]<tmp) swap(mx[u][i],tmp);
    }
    return mx[u][];
}
void dp(int u,int p){
    rep(i,,sz(G[u])){
        int v=G[u][i].se,w=G[u][i].fi;
        if(v==p) continue;
        int tmp;
        if(mx[v][] + w == mx[u][]) tmp = mx[u][] + w;
        else tmp = mx[u][] + w;
        rep(i,,) if(mx[v][i]<tmp) swap(mx[v][i],tmp);
        dp(v,u);
    }
}
int main(){
    int n;
    scanf("%d",&n);
    rep(i,,n+){
        int u,c;
        scanf("%d%d",&u,&c);
        G[u].pb(mp(c,i));
        G[i].pb(mp(c,u));
    }
    dfs(,-);dp(,-);
    rep(i,,n+) printf("%d\n",mx[i][]);
    return ;
}

SGU 196

题意：求AT*A，Aij表示i这个顶点是否是j这个边的端点（是1，不是0）

收获：度是个好东西

#include<bits/stdc++.h>
#define de(x) cout<<#x<<"="<<x<<endl;
#define dd(x) cout<<#x<<"="<<x<<" ";
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define repd(i,a,b) for(int i=a;i>=(b);--i)
#define repp(i,a,b,t) for(int i=a;i<(b);i+=t)
#define ll long long
#define mt(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define pii pair<int,int>
#define pdd pair<double,double>
#define pdi pair<double,int>
#define mp(u,v) make_pair(u,v)
#define sz(a) (int)a.size()
#define ull unsigned long long
#define ll long long
#define pb push_back
#define PI acos(-1.0)
#define qc std::ios::sync_with_stdio(false)
#define db double
#define all(a) a.begin(),a.end()
const int mod = 1e9+;
const int maxn = 1e4+;
const double eps = 1e-;
using namespace std;
bool eq(const db &a, const db &b) { return fabs(a - b) < eps; }
bool ls(const db &a, const db &b) { return a + eps < b; }
bool le(const db &a, const db &b) { return eq(a, b) || ls(a, b); }
ll gcd(ll a,ll b) { return a==?b:gcd(b%a,a); };
ll lcm(ll a,ll b) { return a/gcd(a,b)*b; }
ll kpow(ll a,ll b) {ll res=;a%=mod; if(b<) return ; for(;b;b>>=){if(b&)res=res*a%mod;a=a*a%mod;}return res;}
ll read(){
    ll x=,f=;char ch=getchar();
    while (ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
    while (ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}
    return x*f;
}
//inv[1]=1;
//for(int i=2;i<=n;i++) inv[i]=(mod-mod/i)*inv[mod%i]%mod;
int in[maxn];
int main(){
    int n,m;
    int u,v;
    cin>>n>>m;
    rep(i,,m){
        scanf("%d%d",&u,&v);
        in[u]++,in[v]++;
    }
    int ans = ;
    rep(i,,n+) ans += in[i] * in[i];
    printf("%d\n",ans);
    return ;
}

SGU 302

题意：给你up和down就是up区间里变大写，down变小写

收获：栈

#include<bits/stdc++.h>
#define de(x) cout<<#x<<"="<<x<<endl;
#define dd(x) cout<<#x<<"="<<x<<" ";
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define repd(i,a,b) for(int i=a;i>=(b);--i)
#define repp(i,a,b,t) for(int i=a;i<(b);i+=t)
#define ll long long
#define mt(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define pii pair<int,int>
#define pdd pair<double,double>
#define pdi pair<double,int>
#define mp(u,v) make_pair(u,v)
#define sz(a) (int)a.size()
#define ull unsigned long long
#define ll long long
#define pb push_back
#define PI acos(-1.0)
#define qc std::ios::sync_with_stdio(false)
#define db double
#define all(a) a.begin(),a.end()
const int mod = 1e9+;
const int maxn = 1e3+;
const double eps = 1e-;
using namespace std;
bool eq(const db &a, const db &b) { return fabs(a - b) < eps; }
bool ls(const db &a, const db &b) { return a + eps < b; }
bool le(const db &a, const db &b) { return eq(a, b) || ls(a, b); }
ll gcd(ll a,ll b) { return a==?b:gcd(b%a,a); };
ll lcm(ll a,ll b) { return a/gcd(a,b)*b; }
ll kpow(ll a,ll b) {ll res=;a%=mod; if(b<) return ; for(;b;b>>=){if(b&)res=res*a%mod;a=a*a%mod;}return res;}
ll read(){
    ll x=,f=;char ch=getchar();
    while (ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
    while (ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}
    return x*f;
}
//inv[1]=1;
//for(int i=2;i<=n;i++) inv[i]=(mod-mod/i)*inv[mod%i]%mod;
char s[maxn];
int st[maxn],r=;
char up(char c){
    if(c>='A'&&c<='Z') return c;
    return c - 'a' + 'A';
}
char down(char c){
    if(c>='a'&&c<='z') return c;
    return c - 'A' + 'a';
}
int main(){
    scanf("%s",s+);
    int len = strlen(s+);
    rep(i,,len+){
        if(s[i]=='<'){
            if(s[i+]=='/') {
                r--;
                if(s[i+]=='D') i += ;
                else i += ;
            }else if(s[i+]=='D'){
                i += ;
                st[++r] = ;
            }else {
                i += ;
                st[++r] = ;
            }
            i++;
            continue;
        }
        if(!r){
            printf("%c",s[i]);
        }else if(st[r]==){
            printf("%c",down(s[i]));
        }else {
            printf("%c",up(s[i]));
        }
    }
    return ;
}