第二周 1.24-1.30

1.24

CF 617 C Watering Flowers

sbsbsbsbsbsb

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long LL;
LL x[2222], y[2222], d1[2222], d2[2222];
int n;

LL cal(LL x)
{
    LL ret = 0LL;
    for(int i = 0; i < n; i++)
    {
        if(d1[i] <= x) continue;
        ret = max(ret, d2[i]);
    }
    return ret;
}

int main(void)
{
    LL x1, y1, x2, y2;
    scanf("%d %I64d %I64d %I64d %I64d", &n, &x1, &y1, &x2, &y2);
    for(int i = 0; i < n; i++) scanf("%I64d %I64d", x + i, y + i);
    for(int i = 0; i < n; i++)
    {
        LL xx = x1 - x[i], yy = y1 - y[i];
        d1[i] = xx * xx + yy * yy;
        xx = x2 - x[i], yy = y2 - y[i];
        d2[i] = xx * xx + yy * yy;
    }
    LL ans = cal(0);
    for(int i = 0; i < n; i++)
        ans = min(ans, d1[i] + cal(d1[i]));
    printf("%I64d
", ans);
    return 0;
}

CF 617 E XOR and Favorite Number

逗号和自增混用，位运算和比较的优先级。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long LL;
const int maxn = 1e5 + 10;
int block, a[maxn], b[maxn];
LL cnt[2222222];
LL ans[maxn];

struct query
{
    int id, l, r;
}Q[maxn];

bool cmp(query A, query B)
{
    if(A.l / block != B.l / block) return A.l / block < B.l / block;
    return A.r < B.r;
}

int main(void)
{
    int n, m, k;
    scanf("%d%d%d", &n, &m, &k);
    for(int i = 1; i <= n; i++) scanf("%d", a + i), b[i] = b[i-1] ^ a[i];
    for(int i = 0; i < m; i++) scanf("%d %d", &Q[i].l, &Q[i].r), Q[i].id = i;
    block = sqrt(n), sort(Q, Q + m, cmp);
    LL tmp = 0LL;
    int L = 1, R = 0;
    for(int i = 0; i < m; i++)
    {
        while(R < Q[i].r) {cnt[b[R]]++; R++; tmp += cnt[k^b[R]];}
        while(R > Q[i].r) {tmp -= cnt[k^b[R]]; R--; cnt[b[R]]--;}
        while(L < Q[i].l) {L++; --cnt[b[L-2]]; tmp -= cnt[k^b[L-2]] + ((b[L-2] ^ b[R])== k ? 1LL : 0LL);}
        while(L > Q[i].l) {tmp += cnt[k^b[L-2]] + ((b[L-2] ^ b[R]) == k ? 1LL : 0LL); cnt[b[L-2]]++; L--;}
        ans[Q[i].id] = tmp;
    }
    for(int i = 0; i < m; i++) printf("%I64d
", ans[i]);
    return 0;
}

HDU 5613 Baby Ming and Binary image

DEBUG力丧失。

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int G[33][333], ans[33][333], cpy[33][333];
int n, m;

int cal(int i, int j)
{
    int ret = 0;
    for(int x = -1; x <= 1; x++)
    {
        for(int y = -1; y <= 1; y++)
        {
            int xx = i + x, yy = j + y;
            if(xx < 0 || xx >= n || yy < 0 || yy >= m) continue;
            ret += ans[xx][yy];
        }
    }
    return ret;
}

bool judge(int r)
{
    memset(ans, 0, sizeof(ans));
    for(int i = 1; i < n - 1; i++) ans[i][0] = ( r & (1 << (i-1) ) ) ? 1 : 0 ;
    for(int y = 0; y < m - 1; y++)
    {
        for(int x = 0; x < n - 2; x++)
        {
            int tmp = cal(x, y);
            if(tmp == G[x][y]) continue;
            if(tmp == G[x][y] - 1) ans[x+1][y+1] = 1;
            else return false;
        }
        if(G[n-2][y] != cal(n-2, y) || G[n-1][y] != cal(n-1, y)) return false;
    }
    for(int x = 0; x < n; x++) if(cal(x, m-1)!=G[x][m-1]) return false;
    return true;
}

int main(void)
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        scanf("%d%d", &n, &m);
        for(int i = 0; i < n; i++)
            for(int j = 0; j < m; j++)
                scanf("%d", &G[i][j]);
        int cnt = 0;
        for(int i = 0; i < (1 << (n-2)); i++)
            if(judge(i)) cnt++, memcpy(cpy, ans, sizeof(cpy));
        if(cnt == 1)
        {
            for(int i = 0; i < n; i++)
            {
                for(int j = 0; j < m - 1; j++) printf("%d ", cpy[i][j]);
                printf("%d
", cpy[i][m-1]);
            }
        }
        else if(cnt > 1) puts("Multiple");
        else puts("Impossible");
    }
    return 0;
}

1.25-1.29

什么都没干。

1.30

HDU 5616 Jam's balance

DP写挫。

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int ok[2222], cpy[2222];

int main(void)
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        int N;
        scanf("%d", &N);
        memset(ok, 0, sizeof(ok));
        ok[0] = 1;
        for(int i = 0; i < N; i++)
        {
            int w;
            scanf("%d", &w);
            memcpy(cpy, ok, sizeof(cpy));
            for(int j = 0; j <= 2000; j++)
            {
                if(!cpy[j]) continue;
                ok[j+w] = 1;
                if(j > w) ok[j-w] = 1;
                else ok[w-j] = 1;
            }
        }
        int M;
        scanf("%d", &M);
        while(M--)
        {
            int k;
            scanf("%d", &k);
            if(k > 2000) puts("NO");
            else puts(ok[k] ? "YES" : "NO");
        }
    }
    return 0;
}