河南理工2019暑期选拔赛————我好菜

点击题目即可查看原题
这次的题目都是经典题，
我是个猪吧？

Problem A 小L的项链切割

这题dp

把这一串字符串分成若干个回文串，问切割的次数
也就是问最少能分几串
因为$n<=1000$,所以想应该可以$O(n^2)$
刚开始我是直接找这个串的回文串有多少个，WA, 我又反着找，求最小的，还是wa。就是没有想到dp

令dp[i]表示从字符串从位置1到位置 i ，最少要切割多少次

#include
#include
#include
#include
using namespace std;
const int MAXN = 1e3+7;
int dp[MAXN];
char s[MAXN];

bool check(char *s,int l,int r) {
        while(l<=r) {
                if(s[l]!=s[r])
                        return false;
                l++;
                r--;
        }
        return true;
}

int main() {
        // freopen("../in.txt","r",stdin);
        int t;
        scanf("%d",&t);
        while(t--) {
                scanf("%s",s+1);
                int len = strlen(s+1);
                memset(dp,0,sizeof(dp));
                for(int i=1;i<=len;++i) {
                        dp[i] = MAXN;
                        for(int j=1;j<=i;++j) {
                                if(check(s,j,i)) {
                                        if(j==1)
                                                dp[i] = 1;
                                        else
                                                dp[i] = min(dp[i],dp[j-1]+1);
                                }
                        }
                }
                printf("%d\n",dp[len]-1);
        }
        return 0;
}

Problem B 小L的试卷

这题二分

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;

typedef long long ll;
typedef pair<int ,int> P;

const int INF  = 0x3f3f3f3f;
const int MAXN = 2e4+7;
int a[MAXN];
int l,r;
int total,num;
int n,k;
bool judge(int x) {
        for(int i=0;i<n;++i) {
                if(total+a[i]<=x)       total += a[i];
                else    total = a[i], num++;
        }
        return num>=k;
}


int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        ios::sync_with_stdio(0);
        cin.tie(0);

        while(cin>>n>>k) {
                l = r = 0;
                for(int i=0;i<n;++i) {
                        cin>>a[i];
                        r += a[i];
                        l = max(l,a[i]);
                }
                while(l<=r) {
                        int mid = (l+r)>>1;
                        total = num = 0;
                        if(judge(mid)) l = mid+1;
                        else    r = mid-1;
                }
                cout<<l<<endl;
        }
        return 0;
}

Problem C 小L记单词

这题水

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;

typedef long long ll;
typedef pair<int ,int> P;

const int INF  = 0x3f3f3f3f;
const int MAXN = 1e6+7;


int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        ios::sync_with_stdio(0);
        cin.tie(0);
        string str;
        while(getline(cin,str)) {
                // cout<
                string s="";
                s+=toupper(str[0]);
                for(int i=1;i<str.length();++i) {
                        if(str[i-1]==' ') {
                                s += toupper(str[i]);
                                // cout<
                        }

                }
                cout<<s<<endl;
        }
        return 0;
}

Problem D 小L的取膜算式

这题费马小定理

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;

typedef long long ll;
typedef pair<int ,int> P;
typedef unsigned long long ull;
const int INF  = 0x3f3f3f3f;
const int MAXN = 1e6+7;


int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        // ios::sync_with_stdio(0);
        // cin.tie(0);
        ll t;
        ll a,b;
        ull p;
        scanf("%lld",&t);
        // cin>>t;
        while(t--) {
                scanf("%lld %lld %llu",&a,&b,&p);
                // printf("%lld %lld %llu\n",a,b,p);
                printf("%lld\n",((a+b)%p+p)%p);;
                // cin>>a>>b>>p;
                // cout<<((a+b)%p+p)%p<
        }
        return 0;
}

Problem E 小L玩滚球游戏

这题思维，我做过原题

//#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
 
 
using namespace std;
typedef long long ll;
typedef pair<int ,int> P;
 
const int INF  = 0x3f3f3f3f;
const int MAXN = 1e5+7;
 
ll p[MAXN];
 
int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        ll n,t;
        while(~scanf("%lld %lld",&n,&t)){
                for(int i=0;i<n;++i){
                        ll x,y;
                        scanf("%lld %lld",&x,&y);
                        p[i] = x + y * t;
                }
                ll num = n;
                for(int i=n-1;i>0;--i){
                        if(p[i-1]>=p[i]){
                                p[i-1] = p[i];
                                num--;
                        }
                }
                printf("%lld\n",num);
        }
 
        return 0;
}
 
/**************************************************************
    Problem: 1530
    User: 311709001223
    Language: C++
    Result: 正确
    Time:34 ms
    Memory:2432 kb
****************************************************************/

Problem F 小L的区间求和

这题…,我傻逼

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
 
typedef long long ll;
typedef pair<int ,int> P;
 
const int INF  = 0x3f3f3f3f;
const int MAXN = 1e6+7;
int a[MAXN];
ll sum[MAXN];
int p[MAXN];
int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        ios::sync_with_stdio(0);
        cin.tie(0);
        int n,k;
        while(~scanf("%d %d",&n,&k)) {
                sum[0] = 0;
                int ans = 0;
                memset(p,0,sizeof(p));
                for(int i=0;i<n;++i) {
                        scanf("%d",&a[i]);
                        sum[i+1] = sum[i]+a[i];
                        sum[i+1] %= k;
                        if(sum[i+1]==0) {
                                ans = max(ans,i+1);
                                continue;
                        }
                        if(p[sum[i+1]]==0) p[sum[i+1]] = i+1;
                        ans = max(ans, i+1-p[sum[i+1]]);
                }
                 printf("%d\n",ans);
        }
        return 0;
}
 
/**************************************************************
    Problem: 1531
    User: 311709001223
    Language: C++
    Result: 正确
    Time:8 ms
    Memory:17276 kb
****************************************************************/

Problem G 小L的随机数

这题傻逼

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
 
typedef long long ll;
typedef pair<int ,int> P;
 
const int INF  = 0x3f3f3f3f;
const int MAXN = 1e6+7;
ll x[MAXN];
ll m,a,c,n,g;
 
 
int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        ios::sync_with_stdio(0);
        cin.tie(0);
        while(cin>>m>>a>>c>>x[0]>>n>>g) {
                for(int i=1;i<=n;++i)
                        x[i] = (a*x[i-1]+c)%m;
                cout<<x[n]%g<<endl;
        }
        return 0;
}
 
/**************************************************************
    Problem: 1532
    User: 311709001223
    Language: C++
    Result: 正确
    Time:30 ms
    Memory:9456 kb
****************************************************************/

Problem H 小L的直线

这题傻逼

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
 
typedef long long ll;
// typedef pair P;
 
const int INF  = 0x3f3f3f3f;
const int MAXN = 222;
int x[MAXN],y[MAXN];
double P[MAXN*MAXN];
double p(int i,int j) {
        int dx = x[i] - x[j];
        int dy = y[i] - y[j];
        if(dx)
                return 1.0*dy/dx;
        else
                return INF;
}
int main(){
        int n;
        scanf("%d",&n);
        for(int i=0;i<n;++i)
                scanf("%d %d",&x[i],&y[i]);        
        int cnt = 0;
        for(int i=0;i<n;++i)
                for(int j=i+1;j<n;++j)
                        P[cnt++] = p(i,j);
        sort(P,P+cnt);
        cnt = unique(P,P+cnt)-P;
        printf("%d\n",cnt);
        return 0;
}
 
/**************************************************************
    Problem: 1533
    User: 311709001223
    Language: C++
    Result: 正确
    Time:4 ms
    Memory:2040 kb
****************************************************************/

Problem I 小L的长方形

这题傻逼

// #include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define lp rt<<1
#define rp rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;
 
typedef long long ll;
typedef pair<int ,int> P;
 
const int INF  = 0x3f3f3f3f;
const int MAXN = 1e6+7;
 
 
int main(){
        // freopen("../in.txt","r",stdin);
        // freopen("../out.txt","w",stdout);
        // ios::sync_with_stdio(0);
        // cin.tie(0);
        int a;
        scanf("%d",&a);
        if(a%8==0) {
                int h,l,area;
                h = a/8;
                l = h*3;
                area = h*l;
                printf("%d %d %d\n",l,h,area);
        }
        else {
                double h,l,area;
                h = 1.0*a/8.0;
                l = h*3.0;
                area = h*l;
                printf("%.3lf %.3lf %.3lf\n",l,h,area);
        }
        return 0;
}
 
/**************************************************************
    Problem: 1534
    User: 311709001223
    Language: C++
    Result: 正确
    Time:2 ms
    Memory:1648 kb
****************************************************************/