分治补充oj

 

 

#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
const int maxn = 1e6;
double minx = 0x7fffffff;
int i, j;
double x[maxn], y[maxn];
double dis(double x1, double y1, double x2, double y2)
{
    return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}
int main() 
{
    int n,dn,dm;
    cin >> n;
    double x1, y1, x2, y2;
    for (int i = 0; i < n; i++)
    {
        cin >> x[i] >> y[i];
    }
    for (int i = 0; i < n; i++)
    {
        for (int j = i + 1; j < n; j++)
        {
            double t = dis(x[i], y[i], x[j], y[j]);
            if (minx > t)
            {
                minx=t;
                dn = i;
                dm = j;
            }
        }
    }
    cout << fixed << setprecision(5) << minx << " ";
    cout << fixed << setprecision(1) << x[dn] << " " << y[dn] << " " << x[dm] << " " << y[dm] << endl;
    return 0;
}

---

#include<bits/stdc++.h>
using namespace std;
int a[100005]={0}, b[100005]={0};
int main() {
    int m, n, ans;
    cin >> m >> n;
    for (int i = 1; i <= m; i++) {
        cin >> a[i];
        b[i] = a[i];
    }
    sort(b + 1, b + m + 1);
    ans = b[n];
    for (int i = 1; i <= m; i++) {
        if (a[i] == ans) {
            cout << i;
            break;
        }
    }
    return 0;
}

---

 

#include <iostream>
using namespace std;
#define maxn 10010
int a[maxn];
int main()
{
    int n, m,mid,l,r,f=-1;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    cin >> m;
    l = 1;
    r = n;
    while (l <= r)
    {
        mid = (l + r) / 2;
        if (a[mid] > m)
        {
            r = mid-1;
        }
        else if (a[mid] < m)
        {
            l = mid + 1;
        }
        else
        {
            f = 0;
            break;
        }   
    }
    if (f == 0)
        cout << mid << endl;
    else
        cout << f << endl;
    return 0;
}

---

 

#include <iostream>
using namespace std;
#define maxn 105
int a[maxn][maxn], b[maxn][maxn], c[maxn][maxn];
int n, m, k;
int main()
{
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
        {
            cin >> a[i][j];
        }
    }
    for (int i = 1; i <= m; i++)
    {
        for (int j = 1; j <= k; j++)
        {
            cin >> b[i][j];
        }
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
        {
            for (int w = 1; w <= k; w++)
            {
                c[i][w] += a[i][j] * b[j][w];
            }
        }
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= k; j++)
        {
            cout << c[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}

---

 

#include<bits/stdc++.h>
#include<string>
using namespace std;
int a[1005], b[1005], c[1005];
char s1[1005], s2[1005];
 
int main()
{
    cin >> s1 >> s2;
    int la = strlen(s1);
    int lb = strlen(s2);
 
    for (int i = 0; i < la; i++)
    {
        a[la - i] = s1[i] - '0';
    }
    for (int i = 0; i < lb; i++)
    {
        b[lb - i] = s2[i] - '0';
    }
    int lc = la + lb;
    for (int i = 1; i <= la; i++)
        for (int j = 1; j <= lb; j++)
        {
            c[i + j - 1] += a[i] * b[j];
            c[i + j] += c[i + j - 1] / 10;
            c[i + j - 1] %= 10;
        }
    if (c[lc] == 0 && lc > 0)
        lc--;
    for (int i = lc; i > 0; i--)
        cout << c[i];
    return 0;
}