第十四届蓝桥杯三月真题刷题训练——第 16 天 （3.19）

[Yapink]

第一题：简单啦

#include <iostream>

using namespace std;

int main()
{
    int n;
    cin >> n;
    cout << (char)(n + 64) << endl;
    return 0;
}

#include <iostream>

using namespace std;

int main()
{
    int n;
    cin >> n;
    printf("%c\n", n - 1 + 'A');
    return 0;
}

第二题：先转化为数字，存入数组再比较

#include <iostream>

using namespace std;

// char str[26] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j','k',
//     'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
    
int cnt[26];

int main()
{
    string s;
    cin >> s;
    for (int i = 0; i < s.size(); i ++ ) 
        cnt[s[i] - 'a'] ++ ;
        
    int p = 0;
    for (int i = 1; i <= 26; i ++ ) 
        if (cnt[i] > cnt[p]) p = i;
        
    cout << (char)(p + 'a') << endl << cnt[p] << endl;
    
    return 0;
}

第三题：好难呀，花了好长时间

#include <iostream>

using namespace std;

typedef long long LL;

const int N = 100010;

int n, m, q;
int p[N];
LL d[N];

int find(int x)
{
    if (p[x] != x)
    {
        int t = find(p[x]);
        d[x] += d[p[x]];
        p[x] = t;
    }
    return p[x];
}

int main()
{
    scanf("%d%d%d", &n, &m, &q);
    for (int i = 1; i <= n; i ++ ) p[i] = i;
    
    while (m -- )
    {
        int l, r;
        LL s;
        cin >> l >> r >> s;
        int pa = find(l - 1), pb = find(r);
        if (pa != pb)
        {
            p[pa] = pb;
            d[pa] = d[r] - d[l - 1] - s;
        }
    }
    
    while (q -- )
    {
        int l, r;
        cin >> l >> r;
        int pa = find(l - 1), pb = find(r);
        if (pa != pb) puts("UNKNOWN");
        else cout << d[r] - d[l - 1] << endl;
    }
    return 0;
}