HDOJ 4893 Wow! Such Sequence!（线段树）

本题为一道线段树应用题，但区间更新略有不同。

同时维护两颗线段树，一颗存储原有数串及其区间和，另一颗存储原有数串的最近费波拉契数及这些费波拉契数的区间和。
每一次区间更新不必更新至最底层，直接将该要更新的区间和替换为费波拉契树相应位置的区间和。

AC代码：

#include <iostream>#include <cstdlib>#include <cstdio>#include <cstring>#include <string>#include <cmath>#include <assert.h>#include <algorithm>#define MAX 1234567890#define MIN -1234567890#define eps 1e-8using namespace std;const int maxn = 100100;long long fibo[61];long long sum[maxn<<2], rep[maxn<<2];bool col[maxn<<2];long long search_fibo(long long x, int l, int r){        if(x <= 0) return 1;        for(int i = 1; i < 60; i++)        {                if(fibo[i] <= x && fibo[i+1] >= x)                {                        long long ldis = x - fibo[i];                        long long rdis = fibo[i+1] - x;                        return ldis <= rdis ? fibo[i] : fibo[i+1];                }        }}void push_down(int rt){        if(col[rt])        {                col[rt<<1] = col[rt<<1|1] = col[rt];                sum[rt<<1] = rep[rt<<1];                sum[rt<<1|1] = rep[rt<<1|1];                col[rt] = false;        }}void build(int l, int r, int rt){        if(l == r)        {                rep[rt] = 1;                return ;        }        int m = (l + r) >> 1;        build(l, m, rt<<1);        build(m+1, r, rt<<1|1);        rep[rt] = rep[rt<<1] + rep[rt<<1|1];}void update_point(int p, int add, int l, int r, int rt){        if(l == r)        {                sum[rt] += (long long)add;//                cout << "sum[" << rt << "]: " << sum[rt] << endl;                rep[rt] = search_fibo(sum[rt], 0, 60);//                cout << "rep[" << rt << "]: " << rep[rt] << endl;                return ;        }        push_down(rt);        int m = (l + r) >> 1;        if(p <= m) update_point(p, add, l, m, rt<<1);        else update_point(p, add, m+1, r, rt<<1|1);        sum[rt] = sum[rt<<1] + sum[rt<<1|1];        rep[rt] = rep[rt<<1] + rep[rt<<1|1];}void update_interval(int L, int R, int l, int r, int rt){        if(L <= l && R >= r)        {                col[rt] = true;                sum[rt] = rep[rt];                return ;        }        push_down(rt);        int m = (l + r) >> 1;        if(L <= m) update_interval(L, R, l, m, rt<<1);        if(R > m) update_interval(L, R, m+1, r, rt<<1|1);        sum[rt] = sum[rt<<1] + sum[rt<<1|1];}long long query(int L, int R, int l, int r, int rt){        if(L <= l && R >= r) return sum[rt];        push_down(rt);        int m = (l + r) >> 1;        long long ret = 0;        if(L <= m) ret += query(L, R, l, m, rt<<1);        if(R > m) ret += query(L, R, m+1, r, rt<<1|1);        return ret;}int main(){        #ifdef BellWind        freopen("4893.in", "r", stdin);        #endif // BellWind        fibo[0] = fibo[1] = 1;        for(int i = 2; i <= 60; i++) fibo[i] = fibo[i-1] + fibo[i-2];        int n, m;        while(~scanf("%d%d", &n, &m))        {                memset(sum, 0, sizeof(sum));                memset(col, 0, sizeof(col));                build(1, n, 1);                while(m--)                {                        int op, a, b;                        scanf("%d%d%d", &op, &a, &b);                        if(op == 2) printf("%I64d\n", query(a, b, 1, n, 1));                        if(op == 1) update_point(a, b, 1, n, 1);                        if(op == 3) update_interval(a, b, 1, n, 1);                }        }        return 0;}