分块小集

UVA12003 Array Transformer  

给一列数，每次询问  将 a[ pi ]  的值 更新为  li  到  ri  区间中小于  vi 的个数 *  u / （r-l+1）；

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define ll long long
const int M = 3e5 + 10, SIZE = 4096;
int B[M/SIZE + 1][SIZE + 1], a[M], n;
int read(){
    int x=0,f=1;char c=getchar();
    while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}
    while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}
    return x*=f;    
}
int solve(int L, int R, int v){
    int ret = 0;
    int bl = (L-1)/SIZE, br = (R-1)/SIZE;
    if(bl == br){
        for(int i = L; i <= R; i++) ret += a[i] < v;
        return ret;
    }
    for(int i = L; i <= (bl+1) * SIZE; i++) ret += a[i] < v;
    for(int i = br*SIZE+1; i <= R; i++) ret += a[i] < v;
    for(int i = bl + 1; i < br; i++) ret += lower_bound(B[i] + 1, B[i] + 1 + SIZE, v) - B[i] - 1;
    return ret;
}
void add(int pos, int x){
    if(a[pos] == x)return ;
    int w = (pos-1)/SIZE;
    int tt = 1;
    while(B[w][tt] != a[pos])tt++;
    a[pos] = x;
    B[w][tt] = x;
    while(tt < SIZE && B[w][tt] > B[w][tt+1]) swap(B[w][tt], B[w][tt+1]), tt++;
    while(tt > 1 && B[w][tt] < B[w][tt-1]) 
    swap(B[w][tt], B[w][tt-1]), tt--;
}
int main(){
    //freopen("c.in","r",stdin);
    //freopen("my.out","w",stdout);
    int n, m, u;
    scanf("%d%d%d", &n, &m, &u);
    int blo = 0, j = 0;
    for(int i = 1; i <= n; i++){
        a[i] = read();
        B[blo][++j] = a[i];
        if(j == SIZE){j = 0, blo++;}
    }
    for(int i = 0; i < blo; i++)
        sort(B[i]+1, B[i]+1+SIZE);
    if(j) sort(B[blo]+1, B[blo]+1+j);
    while(m--){
        
        int L = read(), R = read(), v = read(), p = read();
        int k = solve(L, R, v);
        add(p, 1LL*u*k/(R-L+1));
        //for(int i = 1; i <= n; i++)printf("%d ", a[i]);puts("");
    }
    for(int i = 1; i <= n; i++) printf("%d
", a[i]);
}

P4168 [Violet]蒲公英

求区间众数；

// luogu-judger-enable-o2
#include<bits/stdc++.h>
using namespace std;

const int M = 50005;
int cnt[M], a[M], len, n, m, b[M], f[205][205], c[205][M], place[M];

int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}


void init(int x){
    memset(cnt, 0, sizeof(cnt));
    int ans = 0;
    for(int i = x * len + 1; i <= n; i++){
        int bl = place[i];
        cnt[a[i]]++;
        if(cnt[a[i]] > cnt[ans] || (cnt[a[i]] == cnt[ans] && a[i] < ans)) ans = a[i];
        f[x][bl] = ans;
    }
}

int query(int lf, int rg){
    int ans = 0, mx = 0;
    if(place[rg]) ans = f[place[lf]+1][place[rg]-1];
    if(place[rg]) mx = c[place[rg]-1][ans] - c[place[lf]][ans];
    bool fg = place[lf]+1 <= place[rg]-1;
    for(int i = lf; i <= min((place[lf]+1)*len, rg); i++){
        int tt = ++cnt[a[i]]; 
        if(fg) tt += (c[place[rg]-1][a[i]] - c[place[lf]][a[i]]);
        if(tt > mx || (tt == mx && a[i] < ans)) mx = tt, ans = a[i];
    }
    if(place[lf] != place[rg])
        for(int i = place[rg]*len + 1; i <= rg; i++){
            int tt = ++cnt[a[i]];
            if(fg) tt += (c[place[rg]-1][a[i]] - c[place[lf]][a[i]]);
            if(tt > mx || (tt == mx && a[i] < ans)) mx = tt, ans = a[i];
        }
    
    for(int i = lf; i <= min((place[lf]+1)*len, rg); i++)cnt[a[i]] = 0;
    if(place[lf] != place[rg])
        for(int i = place[rg]*len + 1; i <= rg; i++)cnt[a[i]] = 0;        
    return ans;
}


int main(){
    //freopen("c.in","r",stdin);
    //freopen("my.out","w",stdout);
    scanf("%d%d", &n, &m);
    len = sqrt(n + 0.5);
    for(int i = 1; i <= n; i++)a[i] = b[i] = read();
    sort(b + 1, b + 1 + n);
    int tot = unique(b + 1, b + 1 + n) - b - 1;
    for(int i = 1; i <= n; i++){
        a[i] = lower_bound(b + 1, b + 1 + tot, a[i]) - b;
        place[i] = (i - 1)/len;
        c[place[i]][a[i]] = ++cnt[a[i]];
    }
    for(int i = 0; i <= place[n]; i++)init(i);
    for(int i = 1; i <= tot; i++)
        for(int j = 1; j <= place[n]; j++)
            if(!c[j][i]) c[j][i] = c[j - 1][i];
    //for(int i=0;i<=place[n];i++)for(int j=0;j<=place[n];j++)printf("%d ", f[i][j]);
    int lst = 0, l, r;
    memset(cnt, 0, sizeof(cnt));
    while(m--){
        l = read(), r = read();
        l = (l + lst - 1) % n + 1, r = (r + lst - 1) % n + 1;
        if(l > r)swap(l, r);
        lst = b[query(l, r)];
        printf("%d
",lst);
        //printf("%d %d %d
", l, r, lst);
    }
}