zjoi2013day1

k大数查询（线段树套主席树）：

#include <cstdio>#include <cstdlib>#include <cmath>#include <cstring>#include <ctime>#include <algorithm>   #define REP(i, n) for (i = 0; i < (n); ++i)#define int64 long long#define oo 0x13131313#define maxn 50005#define Max(a, b) (a > b ? a : b)#define Min(a, b) (a < b ? a : b)   using namespace std;   struct node { int s, t; node *c[2]; } null[maxn * 100], *nt = null;struct seg { node *R; seg *c[2]; } ss[maxn * 2], *st = ss, *root;int n, m, L, R;   void modify(node *&p, int l, int r){    if (!p || p == null) p = ++nt, p->c[0] = p->c[1] = null;    if (L <= l && r <= R) { p->s += r - l + 1, ++p->t; return; }    int mid = (l + r) >> 1;    if (L <= mid) modify(p->c[0], l, mid);    if (R > mid) modify(p->c[1], mid + 1, r);    p->s += Min(R, r) - Max(L, l) + 1;}   int ask(node *p, int l, int r){    if (!p || p == null) return 0;    if (L <= l && r <= R) return p->s;    int res = 0, mid = (l + r) >> 1;    if (L <= mid) res += ask(p->c[0], l, mid);    if (R > mid) res += ask(p->c[1], mid + 1, r);    return res + p->t * (Min(R, r) - Max(L, l) + 1);}   void build(seg *p, int l, int r){    if (l == r) return;    build(p->c[0] = ++st, l, (l + r) >> 1);    build(p->c[1] = ++st, ((l + r) >> 1) + 1, r);}   void modify(int a, int b, int c){    int l = 1, r = n; seg *p = root; L = a, R = b;    for (; modify(p->R, 1, n), l < r; )        p = c > (l + r) >> 1 ?            (l = ((l + r) >> 1) + 1, p->c[1]) : (r = (l + r) >> 1, p->c[0]);}   int ask(int a, int b, int c){    int l = 1, r = n; seg *p = root; L = a, R = b;    for (; l < r; ) {        int k = ask(p->c[1]->R, 1, n);        p = k < c ? (r = (l + r) >> 1, c -= k, p->c[0]) : (l = ((l + r) >> 1) + 1, p->c[1]);    }    return l;}   int main(){    freopen("sequence.in", "r", stdin);    freopen("sequence.out", "w", stdout);       scanf("%d%d", &n, &m);    build(root = ++st, 1, n);    for (; m--; ) {        int t, a, b, c;        scanf("%d%d%d%d", &t, &a, &b, &c);        t == 1 ? modify(a, b, c), 1 : printf("%d\n", ask(a, b, c));    }}

蚂蚁寻路（dp）：

#include <cstdio>#include <cstdlib>#include <cmath>#include <cstring>#include <ctime>#include <algorithm>#define uns unsigned#define int64 long long#ifdef WIN32#define fmt64 "%I64d"#else#define fmt64 "%lld"#endif#define oo 0x13131313#define REP(i, n) for (i = 0; i < (n); ++i)#define maxim(a, b) ({ int _ = b; if (_ > a) a = _; })using namespace std;int n, m, K, z, ans;int a[101][101], s[101][101];int f[22][101][101][101];int main(){freopen("ant.in", "r", stdin);freopen("ant.out", "w", stdout);int i, j, k, l, q;memset(f, -10, sizeof f), z = ****f;scanf("%d%d%d", &n, &m, &K);for (i = 1; i <= n; ++i)for (j = 1; j <= m; ++j) {scanf("%d", a[i] + j);s[i][j] = s[i - 1][j] + a[i][j];l = 0;for (k = i; k; --k) {f[0][i][j][k] = 0;maxim(f[0][i][j][k], f[0][i][j - 1][k]);f[0][i][j][k] += s[i][j] - s[k - 1][j];}for (l = 1; l < j && l <= K << 1; ++l)if (l & 1) {q = z;for (k = 2; k <= i; ++k) {maxim(q, f[l - 1][i][j - 1][k - 1]);f[l][i][j][k] = q;maxim(f[l][i][j][k], f[l][i][j - 1][k]);f[l][i][j][k] += s[i][j] - s[k - 1][j];}} else {q = z;for (k = i - 1; k; --k) {maxim(q, f[l - 1][i][j - 1][k + 1]);f[l][i][j][k] = q;maxim(f[l][i][j][k], f[l][i][j - 1][k]);f[l][i][j][k] += s[i][j] - s[k - 1][j];}}}ans = -oo;for (i = 1; i <= n; ++i)for (k = 1; k <= i; ++k)for (j = 1; j <= m; ++j)maxim(ans, f[K << 1][i][j][k]);printf("%d\n", ans);}

防守战线（线性规划转费用流）：

#include <cstdio>#include <cstdlib>#include <cmath>#include <cstring>#include <ctime>#include <algorithm> #define uns unsigned#define int64 long long#ifdef WIN32#define fmt64 "%I64d"#else#define fmt64 "%lld"#endif#define oo 0x13131313#define REP(i, n) for (i = 0; i < (n); ++i)#define dual(e) (mem + ((e - mem) ^ 1)) using namespace std; struct edge { int t, f, w; edge *n; }; int n, m, c[1005], S, T;edge mem[40000], *adjc = mem, *adj[1005];int q[1005], dis[1005]; bool vst[1005];int64 cost; void link(int u, int v, int f, int w){    *adjc = (edge) {v, f,  w, adj[u]}, adj[u] = adjc++;    *adjc = (edge) {u, 0, -w, adj[v]}, adj[v] = adjc++;} bool spfa(){    int h, t, k;    memset(vst, 0, T + 1);    memset(dis, -10, (T + 1) << 2), dis[S] = 0, k = dis[0];     for (q[h = t = S] = -1; ~h; vst[h] = 0, h = q[h])        for (edge *e = adj[h]; e; e = e->n)            if (e->f && dis[h] + e->w > dis[e->t])                if (dis[e->t] = dis[h] + e->w, !vst[e->t])                    if (vst[e->t] = 1, ~q[h] && dis[e->t] > dis[q[h]])                        q[e->t] = q[h], q[h] = e->t; else q[t = q[t] = e->t] = -1;    return dis[T] > k;} int dfs(int u, int f){    if (u == T) return f;    int l = f; static int x;    vst[u] = 1;    for (edge *e = adj[u]; e; e = e->n)        if (e->f && !vst[e->t] && dis[e->t] == dis[u] + e->w) {            x = dfs(e->t, f < e->f ? f : e->f);            cost += x * (int64)e->w, f -= x, e->f -= x, dual(e)->f += x;            if (!f) return vst[u] = 0, l;        }    return l - f;} int main(){    int i, j;    scanf("%d%d", &n, &m);    S = n + 1, T = S + 1;    for (i = 1; i <= n; ++i) {        scanf("%d", c + i);        link(i - 1, i, oo, 0);    }    REP(i, n + 1) {        j = c[i] - c[i + 1];        if (j > 0)            link(i, T, j, 0);        else if (j < 0)            link(S, i, -j, 0);    }     for (i = 1; i <= m; ++i) {        int l, r, d;        scanf("%d%d%d", &l, &r, &d);        link(l - 1, r, oo, d);    }     for (; spfa(); )        dfs(S, oo);    printf(fmt64"\n", cost);}