Codeforces Round #340 (Div. 2) A B C D

http://codeforces.com/contest/617
A
尽量选择数值较大的

#include <iostream>#include <stdio.h>#include <string>#include <string.h>#include <cmath>#include <queue>#include <vector>#include <map>#include <set>using namespace std;int main(){    int x;    while (cin>>x)    {        int cnt = 0;        while (x >= 5)        {            x -= 5;            cnt++;        }        while (x >= 4)        {            x -= 4;            cnt++;        }        while (x >= 3)        {            x -= 3;            cnt++;        }        while (x >= 2)        {            x -= 2;            cnt++;        }        while (x >= 1)        {            x -= 1;            cnt++;        }        cout << cnt << endl;    }    return 0;}

B
乘法计数原理

#include <iostream>#include <stdio.h>#include <string>#include <string.h>#include <cmath>#include <queue>#include <vector>#include <map>#include <set>using namespace std;int n;int a[110];long long  b[110];int main(){    while (scanf("%d", &n) != EOF)    {        int ok = 0;        for (int i = 1;i <= n;i++)        {            scanf("%d", &a[i]);            if (a[i] == 1)                ok = 1;        }        if ((n == 1 && a[1] == 0) || !ok)        {            printf("0\n");            continue;        }        memset(b, 1, sizeof(b));        int len = 0;        int c1 = 0;        int cnt = 0;        for (int i = 1;i <= n;i++)        {            if (a[i] == 1)                c1++;            else if (a[i] == 0 && c1 != 0)                cnt++;            if (c1 > 1 && a[i] == 1)            {                b[len++] = cnt + 1;                cnt = 0;            }        }        long long ans = 1;        for (int i = 0;i < len;i++)            ans *= b[i];        printf("%lld\n", ans);    }    return 0;}

C
按与水池1距离大到小模拟

#include <iostream>#include <stdio.h>#include <string>#include <string.h>#include <cmath>#include <queue>#include <vector>#include <map>#include <set>using namespace std;struct Point{    Point() {}    __int64 x, y;}p[10],q[2010];bool cmp(Point a,Point b){    __int64 t1 = (a.x - p[0].x) * (a.x - p[0].x) + (a.y - p[0].y) * (a.y - p[0].y);    __int64 t2 = (b.x - p[0].x) * (b.x - p[0].x) + (b.y - p[0].y) * (b.y - p[0].y);    __int64 t3 = (a.x - p[1].x) * (a.x - p[1].x) + (a.y - p[1].y) * (a.y - p[1].y);    __int64 t4 = (b.x - p[1].x) * (b.x - p[1].x) + (b.y - p[1].y) * (b.y - p[1].y);    if (t1 == t2)        return t3 > t4;    else        return t1 > t2;}  int main(){    int n;    while (scanf("%d", &n) != EOF)    {        for (int i = 0;i < 2;i++)            scanf("%I64d %I64d", &p[i].x, &p[i].y);        for (int i = 0;i < n;i++)            scanf("%I64d %I64d", &q[i].x, &q[i].y);        sort(q, q + n, cmp);        __int64 ans = 1e18, MAX = 0;        for (int i = 0;i < n;i++)        {            ans = min(ans, MAX + (q[i].x - p[0].x) * (q[i].x - p[0].x) + (q[i].y - p[0].y)*(q[i].y - p[0].y));            MAX = max(MAX, (q[i].x - p[1].x) * (q[i].x - p[1].x) +(q[i].y - p[1].y)*(q[i].y - p[1].y));        }        ans = min(ans, MAX);        printf("%I64d\n" ,ans);    }    return 0;}

D
三点一线 - 1
两点一线 另一点不在两点之间区域 - 2
其他 - 3

#include <iostream>#include <stdio.h>#include <string>#include <string.h>#include <cmath>#include <queue>#include <vector>#include <map>#include <set>using namespace std;int x1, x2, x3, y11, y2, y3;bool is_two(int x1, int y1, int x2, int y2, int x3, int y3){    if (x1 == x2)    {        if (y3 <= min(y1, y2) || y3 >= max(y1, y2))            return true;        return false;    }    if (x1 == x3)    {        if (y2 <= min(y1, y3) || y2 >= max(y1, y3))            return true;        return false;    }    if (x3 == x2)    {        if (y1 <= min(y3, y2) || y1 >=max(y3, y2))            return true;        return false;    }    if (y1 == y2)    {        if (x3 <= min(x1, x2) || x3 >= max(x1, x2))            return true;        return false;    }    if (y1 == y3)    {        if (x2 <= min(x1, x3) || x2 >= max(x3, x1))            return true;        return false;    }    if (y3 == y2)    {        if (x1 <= min(x3, x2) || x1 >= max(x3, x2))            return true;        return false;    }    return false;}int main(){    while (cin >> x1 >> y11 >> x2 >> y2 >> x3 >> y3)    {        int ans;        if (x1 == x2 && x1 == x3)            ans = 1;        else if (y11 == y2 && y2 == y3)            ans = 1;        else if (is_two(x1, y11, x2, y2, x3, y3))        {            ans = 2;        }        else            ans = 3;        cout << ans << endl;    }    return 0;}