hdu6155 Subsequence Count

Posted 2020-10-24 poorpool

#include <iostream>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, m, T, uu, vv, ww;
const int mod=1000000007;
char ss[100005];
struct Matrix{
    int ma[3][3];
    Matrix operator * (const Matrix &b)const{
        Matrix re;
        for(int i=0; i<3; i++)
            for(int j=0; j<3; j++){
                re.ma[i][j] = 0;
                for(int k=0; k<3; k++)
                    re.ma[i][j] = (re.ma[i][j] + (ll)ma[i][k]*b.ma[k][j]) % mod;
            }
        return re;
    }
    void reverse(){
        swap(ma[0], ma[1]);
        for(int i=0; i<3; i++)  swap(ma[i][0], ma[i][1]);
    }
}mat[2], dan;
struct SGT{
    Matrix mul[400005];
    int rev[400005];
    void build(int o, int l, int r){
        rev[o] = 0;
        if(l==r)    mul[o] = mat[ss[l]-‘0‘];
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            if(l<=mid)  build(lson, l, mid);
            if(mid<r)   build(rson, mid+1, r);
            mul[o] = mul[lson] * mul[rson];
        }
    }
    void pushDown(int o, int lson, int rson){
        rev[lson] ^= 1;
        rev[rson] ^= 1;
        mul[lson].reverse();
        mul[rson].reverse();
        rev[o] = 0;
    }
    void update(int o, int l, int r, int x, int y){
        if(l>=x && r<=y){
            rev[o] ^= 1;
            mul[o].reverse();
        }
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            if(rev[o])  pushDown(o, lson, rson);
            if(x<=mid)  update(lson, l, mid, x, y);
            if(mid<y)   update(rson, mid+1, r, x, y);
            mul[o] = mul[lson] * mul[rson];
        }
    }
    Matrix query(int o, int l, int r, int x, int y){
        if(l>=x &&r<=y) return mul[o];
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            Matrix ans=dan;
            if(rev[o])  pushDown(o, lson, rson); 
            if(x<=mid)  ans = ans * query(lson, l, mid, x, y);
            if(mid<y)   ans = ans * query(rson, mid+1, r, x, y);
            return ans;
        }
    } 
}sgt;
int main(){
    mat[0].ma[0][0] = 1; mat[0].ma[0][1] = 1; mat[0].ma[0][2] = 1; 
    mat[0].ma[1][0] = 0; mat[0].ma[1][1] = 1; mat[0].ma[1][2] = 0; 
    mat[0].ma[2][0] = 0; mat[0].ma[2][1] = 0; mat[0].ma[2][2] = 1; 
    mat[1].ma[0][0] = 1; mat[1].ma[0][1] = 0; mat[1].ma[0][2] = 0; 
    mat[1].ma[1][0] = 1; mat[1].ma[1][1] = 1; mat[1].ma[1][2] = 1; 
    mat[1].ma[2][0] = 0; mat[1].ma[2][1] = 0; mat[1].ma[2][2] = 1; 
    for(int i=0; i<3; i++)
        for(int j=0; j<3; j++)
            if(i==j)    dan.ma[i][j] = 1;
            else    dan.ma[i][j] = 0;
    cin>>T;
    while(T--){
        cin>>n>>m; 
        scanf("%s", ss+1);
        sgt.build(1, 1, n);
        while(m--){
            scanf("%d %d %d", &ww, &uu, &vv);
            if(ww==1)   sgt.update(1, 1, n, uu, vv);
            else{
                Matrix tmp=sgt.query(1, 1, n, uu, vv);
                printf("%d\n", (tmp.ma[0][2]+tmp.ma[1][2]) % mod); 
            }
        }
    }
    return 0;
}