codeforces round #429 div2

竟然还涨分了。。。rank500+还能涨我rating是有多低。。。

AB不写了

C:类似找规律，具体证明看edtorial

#include<bits/stdc++.h>
using namespace std;
const int N = 200010;
int m;
struct data {
    int b, id;
    bool friend operator < (data A, data B)
    {
        return A.b < B.b;
    }
} x[N], y[N];
int ans[N];
int main()
{
    scanf("%d", &m);
    for(int i = 1; i <= m; ++i) 
    {
        scanf("%d", &x[i].b);
        x[i].id = i;
    }
    for(int i = 1; i <= m; ++i)
    {
        scanf("%d", &y[i].b);
        y[i].id = i;
    }
    sort(y + 1, y + m + 1);
    sort(x + 1, x + m + 1);
    for(int i = 1; i <= m; ++i) ans[y[i].id] = x[m - i + 1].b;
    for(int i = 1; i <= m; ++i) printf("%d ", ans[i]);
    return 0;
}

D:首先度数是奇数是不行的，这样是无解，所以我们拿出一个-1让度数变成偶数，然后实行染色，如果当前度数和是偶数就不连，是奇数就得连

#include<bits/stdc++.h>
using namespace std;
const int N = 300010;
int n, m, cnt;
int a[N], vis[N], b[N];
vector<int> G[N], e[N], ans;
bool flag;
void dfs(int u)
{
    vis[u] = 1;
    if(a[u] == 1) b[u] = 1;
    for(int i = 0; i < G[u].size(); ++i)
    {
        int v = G[u][i];
        if(vis[v]) continue;
        dfs(v);
        if(b[v] & 1) ans.push_back(e[u][i]);
        b[u] += b[v];
    }
}
int main()
{
    int pos = -1;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; ++i) 
    {
        scanf("%d", &a[i]);
        if(a[i] == 1) ++cnt;
        if(a[i] == -1) pos = i;
    }
    for(int i = 1; i <= m; ++i)
    {
        int u, v;
        scanf("%d%d", &u, &v);
        G[u].push_back(v);
        G[v].push_back(u);
        e[u].push_back(i);
        e[v].push_back(i);
    }
    if(cnt & 1)
    {
        if(pos == -1)
        {
            puts("-1");
            return 0;
        }
        a[pos] = 1;
    }
    dfs(1);
    printf("%d\n", ans.size());
    sort(ans.begin(), ans.end());
    for(int i = 0; i < ans.size(); ++i) printf("%d\n", ans[i]);
    return 0;
}

editorial给太晚，差评