Codeforces Round #424 (Div. 2) A-C

Posted 2020-10-02 Hyouka

A. Unimodal Array

水题

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INFLL   0x3f3f3f3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;
typedef pair<double, double> PII;

const int maxn = 100 + 5;

int a[maxn];
int b[maxn];

int main() {
    //FIN
    int n;
    cin >> n;
    for(int i = 1; i <= n; i++) cin >> a[i];
    for(int i = 1; i <= n -1; i++) {
        if(a[i] - a[i + 1] > 0) b[i] = 1;
        else if(a[i] - a[i + 1] == 0) b[i] = 0;
        else if(a[i] - a[i + 1] < 0) b[i] = -1;
    }
    for(int i = 1; i <= n - 2; i++) {
        //cout << b[i]<<"  ";
        if(b[i + 1] < b[i]) {
            cout <<"NO"<<endl;
            return 0;
        }
    }
    cout <<"YES"<<endl;
    return 0;
}

　　

B. Keyboard Layouts

比第一题还水...

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INFLL   0x3f3f3f3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;
typedef pair<double, double> PII;

char s1[30];
char s2[30];
char s3[1005];

int main() {
    //FIN
    cin >> s1;
    cin >> s2;
    cin >> s3;
    int len = strlen(s3);
    for(int i = 0; i < len; i++) {
        int flag = 0;
        if(s3[i] >= ‘0‘ && s3[i] <= ‘9‘) {
            cout << s3[i];
            continue;
        }
        if(s3[i] >= ‘A‘ && s3[i] <= ‘Z‘) {
            flag = 1;
            s3[i] += 32;
        }
        for(int j = 0; j < 26; j++) {
            if(s1[j] == s3[i]) {
                if(flag) printf("%c", s2[j] - 32);
                else cout << s2[j] ;
                break;
            }
        }

    }

    return 0;
}

　　

C. Jury Marks

这题看了题解才会做 学会了一个新操作 unique

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INFLL   0x3f3f3f3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;
typedef pair<double, double> PII;

const int maxn = 2000 + 5;

int a[maxn];
int b[maxn];
int sum[maxn];

vector<int> vec;
map<int, int> mp;

int main() {
    //FIN
    int n, k;
    scanf("%d%d", &k, &n);
    int x;
    for(int i = 1; i <= k; i++) {
        scanf("%d", &a[i]);
        sum[i] += sum[i - 1] + a[i];
    }

    sort(sum + 1, sum + 1 + k);
    int len = unique(sum + 1, sum + 1 + k) - (sum + 1);

    for(int i = 1; i <= n; i++) {
        scanf("%d", &b[i]);
        for(int j = 1; j <= len; j++) {
            int tmp = b[i] - sum[j];
            vec.push_back(tmp);
        }
    }

    sort(vec.begin(), vec.end());

    for(int i = 0; i < vec.size(); i++) {
        mp[vec[i]]++;
    }

    int ans = 0;

    for(int i = 0; i < vec.size(); i++) {
        if(mp[vec[i]] >= n) {
            ans++;
            mp[vec[i]] = 0;
        }
    }
    printf("%d\n", ans);

    return 0;
}