【樹狀數組】樹狀數組複習

poj2155 Matrix
/***************************\
 * @prob: poj2155 Matrix   *
 * @auth: Wang Junji       *
 * @stat: Accepted.        *
 * @date: May. 29th, 2012  *
 * @memo: 樹狀數組          *
\***************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 1010;
bool a[maxN][maxN]; int n, m, T;

inline void modify(int x, int y)
{
    for (int i = x; i; i -= i & -i)
    for (int j = y; j; j -= j & -j)
        a[i][j] ^= 1;
    return;
}

inline bool query(int x, int y)
{
    bool ans = 0;
    for (int i = x; i < n + 1; i += i & -i)
    for (int j = y; j < n + 1; j += j & -j)
        ans ^= a[i][j];
    return ans;
}

int main()
{
    freopen("Matrix.in", "r", stdin);
    freopen("Matrix.out", "w", stdout);
    scanf("%d", &T);
    while (T--)
    {
        scanf("%d%d", &n, &m);
        for (int i = 1; i < n + 1; ++i)
        for (int j = 1; j < n + 1; ++j)
            a[i][j] = 0;
        while (m--) switch (scanf("\n"), getchar())
        {
        case 'C':
            {
                int x0, y0, x1, y1;
                scanf("%d%d%d%d", &x0, &y0, &x1, &y1);
                modify(x1, y1);
                modify(x0 - 1, y1);
                modify(x1, y0 - 1);
                modify(x0 - 1, y0 - 1);
            }
            break;
        case 'Q':
            {
                int x, y;
                scanf("%d%d", &x, &y);
                printf("%d\n", query(x, y));
            }
            break;
        }
        printf("\n");
    }
    return 0;
}

/*

詢問的是某個點,改變的是區間,只需要用遞減式枚舉來修改,用遞增式枚舉來詢問即可。

*/
poj3321 Apple Tree

/*******************************\
 * @prob: poj3321 Apple Tree   *
 * @auth: Wang Junji           *
 * @stat: Accepted.            *
 * @date: May. 30th, 2012      *
 * @memo: 樹狀數組、維護Dfs序     *
\*******************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 100010;
struct Edge
{
    int v; Edge *next; Edge() {}
    Edge(int v, Edge *next): v(v), next(next) {}
} *edge[maxN];
bool ex[maxN]; int a[maxN], DFN[maxN], sz[maxN], n, m;

void Dfs(int u, int Last)
{
    static int tot = 0; DFN[u] = ++tot; sz[u] = 1;
    for (Edge *p = edge[u]; p; p = p -> next) if (p -> v - Last)
        Dfs(p -> v, u), sz[u] += sz[p -> v];
    return;
}

inline void chg(int x)
{
    ex[x] ^= 1;
    for (int i = DFN[x]; i < n + 1; i += i & -i) ex[x] ? ++a[i] : --a[i];
    return;
}

inline int sum(int x)
{
    int ans = 0;
    for (int i = DFN[x] + sz[x] - 1; i; i -= i & -i) ans += a[i];
    for (int i = DFN[x] - 1; i; i -= i & -i) ans -= a[i];
    return ans;
}

int main()
{
    freopen("Apple_Tree.in", "r", stdin);
    freopen("Apple_Tree.out", "w", stdout);
    scanf("%d", &n);
    for (int i = 1, u, v; i < n; ++i)
    {
        scanf("%d%d", &u, &v);
        edge[u] = new Edge(v, edge[u]);
        edge[v] = new Edge(u, edge[v]);
    }
    Dfs(1, 0); for (int i = 1; i < n + 1; ++i) chg(i);
    scanf("%d", &m);
    for (int x; m--;) switch (scanf("\n"), getchar())
    {
    case 'C': scanf("%d", &x); chg(x); break;
    case 'Q': scanf("%d", &x); printf("%d\n", sum(x)); break;
    }
    return 0;
}
poj2481 Cows

/*****************************\
 * @prob: poj2481 Cows       *
 * @auth: Wang Junji         *
 * @stat: Accepted.          *
 * @date: May. 31st, 2012    *
 * @memo: 樹狀數組            *
\*****************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 100010;
int a[maxN], ans[maxN], L[maxN], R[maxN], ord[maxN], n, N;

inline int getint()
{
    int res = 0; char tmp;
    while (!isdigit(tmp = getchar()));
    do res = (res << 3) + (res << 1) + tmp - '0';
    while (isdigit(tmp = getchar()));
    return res;
}

inline bool cmp(const int &a, const int &b)
{return R[a] > R[b] || (R[a] == R[b] && L[a] < L[b]);}

inline void Add(int x)
{for (int i = x; i < N + 1; i += i & -i) ++a[i]; return;}

inline int sum(int x)
{
    int ans = 0;
    for (int i = x; i; i -= i & -i) ans += a[i];
    return ans;
}

int main()
{
    freopen("cow.in", "r", stdin);
    freopen("cow.out", "w", stdout);
    while (n = getint())
    {
        memset(a, 0, sizeof a); N = 0;
        for (int i = 0; i < n; ord[i] = i, ++i)
            N = std::max(N, L[i] = getint() + 1), R[i] = getint() + 1;
        std::sort(ord, ord + n, cmp);
        for (int i = 0, ths; i < n; ++i)
        {
            ths = ans[ord[i]] = sum(L[ord[i]]), Add(L[ord[i]]);
            while (L[ord[i + 1]] == L[ord[i]]
                    && R[ord[i + 1]] == R[ord[i]])
                ans[ord[++i]] = ths, Add(L[ord[i]]);
            //計算後面相同的區間。
        }
        for (int i = 0; i < n; ++i) printf("%d ", ans[i]);
        printf("\n");
    }
    return 0;
}

/*

先把區間按右界從大到小排序(右界相同時按左界從小到大排序),然後按照Stars的做法繼續做。

注意多個完全相同的區間在一起時,要同時把他們都計算出來,並且多次計數。

*/

poj3067 Japan

/***************************\
 * @prob: poj3067 Japan    *
 * @auth: Wang Junji       *
 * @stat: Accepted.        *
 * @date: May. 31st, 2012  *
 * @memo: 樹狀數組         *
\***************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 1000010;
int L[maxN], R[maxN], ord[maxN], n, m, K;
long long a[maxN], ans;

inline int getint()
{
    int res = 0; char tmp;
    while (!isdigit(tmp = getchar()));
    do res = (res << 3) + (res << 1) + tmp - '0';
    while (isdigit(tmp = getchar()));
    return res;
}

inline bool cmp(const int &a, const int &b)
{return R[a] > R[b] || (R[a] == R[b] && L[a] > L[b]);}

inline void Add(int x)
{for (int i = x; i < n + 1; i += i & -i) ++a[i]; return;}

inline long long sum(int x)
{
    long long ans = 0;
    for (int i = x; i; i -= i & -i) ans += a[i];
    return ans;
}

int main()
{
    freopen("Japan.in", "r", stdin);
    freopen("Japan.out", "w", stdout);
    for (int T = getint(), t = 0; t < T;)
    {
        memset(a, 0, sizeof a); ans = 0;
        n = getint(); m = getint(); K = getint();
        for (int i = 0; i < K; ord[i] = i, ++i)
            L[i] = getint(), R[i] = getint();
        std::sort(ord, ord + K, cmp);
        for (int i = 0; i < K; ++i)
            ans += sum(L[ord[i]] - 1), Add(L[ord[i]]);
        printf("Test case %d: %lld\n", ++t, ans);
    }
    return 0;
}

/*

先按第二個座標從大到小排序(若第二個座標相同則按第一個座標從大到小排序),然後按照Stars或者Cow的做法繼續做就是了。

看錯一個題目條件,"At most two superhighways cross at one location."並不一定是一個城市只向兩個城市建設高速公路。
數組要開夠,10^6。
要用long long類型存儲。

*/
poj2029 Get Many Persimmon Trees
/********************************************\
 * @prob: poj2029 Get Many Persimmon Trees  *
 * @auth: Wang Junji                        *
 * @stat: Accepted                          *
 * @date: May. 31th, 2012                   *
 * @memo: 二維樹狀數組                        *
\********************************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 1010;
int a[maxN][maxN], n, m, K;

inline int getint()
{
    int res = 0; char tmp;
    while (!isdigit(tmp = getchar()));
    do res = (res << 3) + (res << 1) + tmp - '0';
    while (isdigit(tmp = getchar()));
    return res;
}

inline void Add(int x, int y)
{
    for (int i = x; i < n + 1; i += i & -i)
    for (int j = y; j < m + 1; j += j & -j)
        ++a[i][j];
    return;
}

inline int sum(int x, int y)
{
    int ans = 0;
    for (int i = x; i; i -= i & -i)
    for (int j = y; j; j -= j & -j)
        ans += a[i][j];
    return ans;
}

int main()
{
    freopen("tree.in", "r", stdin);
    freopen("tree.out", "w", stdout);
    while (K = getint())
    {
        n = getint(); m = getint();
        memset(a, 0, sizeof a);
        for (int i = 0; i < K; ++i)
        {
            int x = getint(), y = getint();
            Add(x, y);
        }
        int N = getint(), M = getint(), ans = 0;
        for (int i = N; i < n + 1; ++i)
        for (int j = M; j < m + 1; ++j)
            ans = std::max(ans,
                    sum(i, j) + sum(i - N, j - M)
                    - sum(i - N, j) - sum(i, j - M));
        printf("%d\n", ans);
    }
    return 0;
}

poj1990 MooFest

/***************************\
 * @prob: poj1990 MooFest  *
 * @auth: Wang Junji       *
 * @stat: Accepted.        *
 * @date: May. 31st, 2012  *
 * @memo: 樹狀數組          *
\***************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 200010;
typedef long long int64;
struct Cow {int vol, x;} cow[maxN];
int64 cnt_x[maxN], sum_x[maxN], ans, tot;
int n, N;

inline bool cmp(const Cow &a, const Cow &b)
{return a.vol < b.vol;}

inline void Add(int64 *a, int x, int delta)
{for (int i = x; i < N; i += i & -i) a[i] += delta; return;}

inline int64 sum(int64 *a, int x)
{
    int64 ans = 0;
    for (int i = x; i; i -= i & -i) ans += a[i];
    return ans;
}

int main()
{
    freopen("MooFest.in", "r", stdin);
    freopen("MooFest.out", "w", stdout);
    scanf("%d", &n);
    for (int i = 0; i < n; ++i)
        scanf("%d%d", &cow[i].vol, &cow[i].x),
        N = std::max(N, cow[i].x + 1);
    std::sort(cow, cow + n, cmp);
    for (int i = 0; i < n; tot += cow[i].x, ++i)
        ans += cow[i].vol * (((sum(cnt_x, cow[i].x - 1) << 1) - i)
            * cow[i].x + tot - (sum(sum_x, cow[i].x - 1) << 1)),
        Add(cnt_x, cow[i].x, 1), Add(sum_x, cow[i].x, cow[i].x);
    printf("%lld\n", ans);
    return 0;
}

/*

用按音量排序(爲了保證每次都用較大音量奶牛的音量來計算),用兩個樹狀數組分別維護在當前奶牛左邊的奶牛的個數以及橫座標之和。

那麼每次左右兩邊分別計算距離之和(左邊的奶牛數 * x - 左邊的奶牛橫座標之和 + 右邊的奶牛橫座標之和 - 右邊的奶牛數 * x)再乘上當前奶牛的音量並累加即可。

其中,右邊的奶牛橫座標之和 = 比當前奶牛音量小的奶牛的橫座標之和 - 左邊的奶牛橫座標之和;
右邊的奶牛數 = 比當前奶牛音量小的奶牛的橫座標之和 - 左邊的奶牛數。

注意要用long long類型存儲。

*/
hdu1166 敵兵佈陣

/****************************\
 * @prob: hdu1166 敵兵佈陣   *
 * @auth: Wang Junji        *
 * @stat: Accepted.         *
 * @date: June. 21st, 2012  *
 * @memo: 樹狀數組           *
\****************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 50010;

int a[maxN], n, T; char str[20];

inline void Add(int x, int val)
{
    for (int i = x; i < n + 1; i += i & -i) a[i] += val;
    return;
} /* Add */

inline int calc(int x)
{
    int res = 0;
    for (int i = x; i; i -= i & -i) res += a[i];
    return res;
} /* calc */

int main()
{
    freopen("enemy.in", "r", stdin);
    freopen("enemy.out", "w", stdout);
    scanf("%d", &T);
    while (T--)
    {
        scanf("%d", &n); int tmp, x, y; memset(a, 0, sizeof a);
        for (int i = 1; i < n + 1; ++i) scanf("%d", &tmp), Add(i, tmp);
        static int Case = 0; printf("Case %d:\n", ++Case);
        while (scanf("%s", str), strcmp(str, "End"))
        {
            scanf("%d%d", &x, &y);
            if (!strcmp(str, "Query")) printf("%d\n", calc(y) - calc(x - 1));
            else if (!strcmp(str, "Add")) Add(x, y); else Add(x, -y);
        } /* while */
    } /* while */
    return 0;
} /* main */

/*

樹狀數組的入門題,不再多說。

*/
hdu3333 Turning Tree

/********************************\
 * @prob: hdu3333 Turning Tree  *
 * @auth: Wang Junji            *
 * @stat: Accepted.             *
 * @date: June. 22nd, 2012      *
 * @memo: 樹狀數組、離散化處理     *
\********************************/
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <string>

const int maxN = 100010;
typedef long long int64;
struct Seg
{
    int L, R, ord; Seg() {} /* Seg */
    Seg(int L, int R, int ord): L(L), R(R), ord(ord) {} /* Seg */
    bool operator<(const Seg& b) const
    {return R < b.R || (R == b.R && L < b.L);}
    /* operator< */
} seg[maxN]; int64 tr[maxN], res[maxN];
int num[maxN], tab[maxN], pre[maxN], n, m, T;

inline void Add(int x, int val)
{
    for (int i = x; i && i < n + 1; i += i & -i) tr[i] += val;
    return;
} /* Add */

inline int64 calc(int x)
{
    int64 res = 0;
    for (int i = x; i; i -= i & -i) res += tr[i];
    return res;
} /* calc */

int main()
{
    freopen("tree.in" , "r", stdin );
    freopen("tree.out", "w", stdout);
    for (scanf("%d", &T); T--;)
    {
        scanf("%d", &n);
        for (int i = 1; i < n + 1; ++i)
            scanf("%d", num + i), tab[i - 1] = num[i];
        std::sort(tab, tab + n);
        int cnt = std::unique(tab, tab + n) - tab;
        scanf("%d", &m);
        for (int i = 0, L, R; i < m; ++i)
            scanf("%d%d", &L, &R), seg[i] = Seg(L, R, i);
        std::sort(seg, seg + m);
        int pos = 0;
        memset(pre, 0, sizeof pre);
        memset(tr , 0, sizeof tr );
        for (int i = 0; i < m; ++i)
        {
            while (pos < seg[i].R)
            {
                int Index = std::lower_bound(tab, tab + cnt, num[++pos]) - tab;
                Add(pre[Index]      , -num[pos]);
                Add(pre[Index] = pos,  num[pos]);
            } /* while */
            res[seg[i].ord] = calc(seg[i].R) - calc(seg[i].L - 1);
        } /* for */
        for (int i = 0; i < m; ++i) printf("%lld\n", res[i]);
    } /* for */
    return 0;
} /* main */

/*

剛看了題,就開始想在線算法,發現沒法做。

一不小心看了一篇題解之後頓悟。

將所有詢問的區間按照右界從小到大的順序排序,記錄每個數上一次出現的位置,每次將之前位置的數刪掉,加入最新,用樹狀數組求和即可。

*/

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