2016年中国大学生程序设计竞赛（杭州） 部分题解

【题解可以看这里，我提供了部分题的代码】点击打开链接

【A】

【代码】

#include <bits/stdc++.h>using namespace std;typedef long long LL;int a[500000];LL sum[500000];int main(){    int T, ks = 1;    scanf("%d",&T);    while(T--)    {        int n, m;        scanf("%d%d",&n,&m);        sum[0] = 0;        LL ans = 0;        for(int i = 1; i <= n; i++)        {            scanf("%d",&a[i]);            sum[i] = sum[i-1] + 1LL*a[i];            ans += a[i];        }        if(ans % m)        {            printf("Case #%d: -1\n",ks++);            continue;        }        int t = 0;        ans  = ans / m;        for(int i = 1; i < n; i++)        {            if(sum[i] % ans == 0) t -= 2;        }        t = t + n - 1 + m - 1;        printf("Case #%d: %d\n",ks++,t);    }    return 0;}

【B】

【代码】

////Created by just_sort 2016/10/28//Copyright (c) 2016 just_sort.All Rights Reserved//#include <ext/pb_ds/assoc_container.hpp>#include <ext/pb_ds/tree_policy.hpp>#include <ext/pb_ds/hash_policy.hpp>#include <set>#include <map>#include <queue>#include <stack>#include <cmath>#include <cstdio>#include <cstdlib>#include <cstring>#include <iostream>#include <algorithm>using namespace std;using namespace __gnu_pbds;typedef long long LL;typedef pair<int, LL> pp;#define MP(x,y) make_pair(x,y)const int maxn = 200005;const int N = 1005;const int M = 2010;const int inf = 0x3f3f3f3f;typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>order_set;//headint indgree[maxn],pre[maxn],lowlink[N],sccno[N],dfs_clock,scc_cnt,maxc[maxn],ans;struct node{    LL x, y, r;    int c;}a[N];vector <int> E[N];vector <int> G[N];//new graph.stack <int> s;void init(){    memset(indgree, 0, sizeof(indgree));    ans = 0;}void dfs(int u){    pre[u] = lowlink[u] = ++dfs_clock;    s.push(u);    for(int i = 0; i < E[u].size(); i++)    {        int v = E[u][i];        if(!pre[v])        {            dfs(v);            lowlink[u] = min(lowlink[u], lowlink[v]);        }        else if(!sccno[v])            lowlink[u] = min(lowlink[u], pre[v]);    }    if(lowlink[u] == pre[u])    {        scc_cnt++;        for(;;)        {            int x = s.top(); s.pop();            sccno[x] = scc_cnt;            maxc[scc_cnt] = min(maxc[scc_cnt], a[x].c);            if(x == u) break;        }    }}void suodian(int n){    dfs_clock = scc_cnt = 0;    memset(sccno, 0, sizeof(sccno));    memset(pre, 0, sizeof(pre));    while(!s.empty()) s.pop();    for(int i = 1; i <= n; i++)    {        if(!pre[i])        {            dfs(i);        }    }}bool check(int i, int j){    double d = sqrt(1.0*(a[i].x-a[j].x)*(a[i].x-a[j].x) + 1.0*(a[i].y-a[j].y)*(a[i].y-a[j].y));    if(1.0*a[i].r >= d) return 1;    else return 0;}int main(){    int T,n,ks = 1;    scanf("%d",&T);    while(T--)    {        scanf("%d",&n);        init();        for(int i = 0; i <= n; i++) E[i].clear();        for(int i = 0; i <= n; i++) G[i].clear();        for(int i = 0; i <= n; i++) maxc[i] = inf;        for(int i = 1; i <= n; i++) scanf("%lld%lld%lld%d",&a[i].x,&a[i].y,&a[i].r,&a[i].c);        for(int i = 1; i <= n; i++){            for(int j = 1; j <= n; j++){                if(i == j) continue;                if(check(i,j)) E[i].push_back(j);            }        }        suodian(n);        for(int i = 1; i <= n; i++){            for(int j = 0; j < E[i].size(); j++){                int v = E[i][j];                if(sccno[i] != sccno[v]){                    indgree[sccno[v]]++;                    G[sccno[i]].push_back(sccno[v]);                }            }        }        for(int i = 1; i <= scc_cnt; i++)        {            if(!indgree[i])            {                ans += maxc[i];            }        }        printf("Case #%d: %d\n",ks++, ans);    }    return 0;}

【C】

注意卡精度！

【代码】

#include <bits/stdc++.h>using namespace std;typedef long long LL;int n, a[100010];const double eps = 1e-8;int main(){    int T,ks = 1;    scanf("%d",&T);    while(T--)    {        scanf("%d",&n);        for(int i = 1; i <= n; i++) scanf("%d",&a[i]);        double v = a[n] - a[n-1];        int  ans = 1;        double x;        for(int i = n - 1; i; i--)        {            x = a[i] - a[i-1];            if(x <= v + eps)            {                v = x;                ans++;            }            else            {                ans += (int(double(x - eps)/v) + 1);                v = (double(x)/(int(double(x-eps)/v)+1));            }        }        printf("Case #%d: %d\n",ks++,ans);    }}

【F】

【代码】

#include <bits/stdc++.h>using namespace std;typedef long long LL;const LL inf = 1e20;char s[22];int a[22];int main(){    int T,ks=1;    scanf("%d",&T);    while(T--)    {        scanf("%s",s);        int len = strlen(s);        memset(a, 0, sizeof(a));        for(int i = 0; i < len; i++){            a[i+1] = s[i] - '0';        }        LL ans = -inf;        LL t1 = 0;        LL t2 = 0;        LL t3 = 0;        LL t4 = 0;        LL t5 = 0;        for(int i = 2;  (i+3)<= len; i++){            for(int j = i+1; (j+2) <= len; j++){                int k = j + 1;                int l = k + 1;                t1 = t2 = t3 = t4 = t5 = 0;                for(int t = 1; t < i; t++) t1 = t1*10 + 1LL*a[t];                for(int t = i; t < j; t++) t2 = t2*10 + 1LL*a[t];                for(int t = j; t < k; t++) t3 = t3*10 + 1LL*a[t];                for(int t = k; t < l; t++) t4 = t4*10 + 1LL*a[t];                for(int t = l; t <= len; t++) t5 = t5*10 + 1LL*a[t];                //cout<<t1<<" "<<t2<<" "<<t3<<" "<<t4<<" "<<t5<<endl;                ans = max(ans, t1 + t2 - 1LL*(t3*t4)/t5);            }        }        printf("Case #%d: %I64d\n",ks++,ans);    }}

【K】

【代码】

#include <bits/stdc++.h>using namespace std;typedef long long LL;const int maxn = 2000;vector<int>g[maxn];int from[maxn];bool used[maxn];bool match(int x){    for(int i = 0; i < (int)g[x].size(); i++){        if(!used[g[x][i]]){            used[g[x][i]] = true;            if(from[g[x][i]] == -1 || match(from[g[x][i]]))            {                from[g[x][i]] = x;                return true;            }        }    }    return false;}int main(){    int T, ks = 1;    scanf("%d",&T);    while(T--)    {        int s, n;        scanf("%d%d",&s,&n);        if(s < n) swap(s, n);        if(n > 500)        {            printf("Case #%d: No\n",ks++);            continue;        }        for(int i = 0; i < maxn; i++) g[i].clear();        memset(from, -1, sizeof(from));        int tot = 0;        for(int i = 1; i <= n; i++){            int t = i + s;            for(int j = 1; j <= n; j++){                if(t % j == 0){                    g[i].push_back(j);                }            }        }        for(int i = 1; i <= n; i++)        {            memset(used,0,sizeof(used));            if(match(i)){                tot++;            }        }        if(tot == n){            printf("Case #%d: Yes\n",ks++);        }        else        {            printf("Case #%d: No\n",ks++);        }    }}