UVa 10432 10696 10783 10812 10921 10931 10970 11150 11172 11185

10432 Polygon Inside A Circle.c

#include <stdio.h>
#include <math.h>

int main()
{
    double n, r, area;

    while (scanf("%lf %lf", &r, &n) == 2)
    {
        area = n * r * r * sin(2 * 3.141592653589793238462643383279 / n) / 2;
        printf("%.3lf\n", area);
    }
    return 0;
}

10696 f91.c

#include <stdio.h>

int f91 (int n);

int main()
{
    int n, num;

    while(scanf("%d", &n) == 1)
    {
        if(n == 0)break;
        num = f91(n);
        printf("f91(%d) = %d\n", n, num);
    }
    return 0;
}

int f91 (int n)
{
    if (n >= 101) return n - 10;
    else return 91;
}

10783 odd sum.c

#include <stdio.h>

int main()
{
    int a, b, i = 0, n, c, d = 0, sum, temp;

    scanf("%d", &n);

    while (i < n)
    {
        sum = 0;

        scanf("%d %d", &a, &b);

        temp = a;

        c = a % 2;

        while (c == 1)
        {
            sum = sum + temp;
            temp = temp + 2;

            if ((temp == (b + 1)) || (temp == (b + 2))) c = 2;
        }

        if (c == 0)
        {
            d = 1;
            temp = a + 1;
        }

        while (d == 1)
        {

            sum = sum + temp;
            temp = temp + 2;

            if ((temp == (b + 1)) || (temp == (b + 2))) d = 2;
        }

        printf("Case %d: %d\n", i + 1, sum);

        i++;
    }
    return 0;
}

10812 Beat the Spread!.c

#include <stdio.h>

int main()
{
    int n, i, sum, dif, a, b, add;

    scanf("%d", &n);

    for (i = 0; i < n; ++i)
    {
        scanf("%d %d", &sum, &dif);
        add = sum + dif;

        if (sum >= dif && add % 2 == 0)
        {
            a = add / 2;
            b = sum - a;
            printf("%d %d\n", a, b);
        }
        else printf("impossible\n");
    }
    return 0;
}

10812 Beat the Spread.c

#include <stdio.h>

int main()
{
    int n, i, sum, dif, a, b, add;

    scanf("%d", &n);

    for (i = 0; i < n; ++i)
    {
        scanf("%d %d", &sum, &dif);
        add = sum + dif;

        if (sum >= dif && add % 2 == 0)
        {
            a = add / 2;
            b = sum - a;
            printf("%d %d\n", a, b);
        }
        else printf("impossible\n");
    }
    return 0;
}

10921 Find the Telephone.c

#include <stdio.h>
#include <string.h>

int main()
{
    int i, j, k, len;
    char ch[1000];

    while (scanf("%s", ch) == 1)
    {
        len = strlen(ch);
        for (i = 0; i < len; ++i)
            switch (ch[i])
            {
            	case 'A':
            	case 'B':
            	case 'C':
                    ch[i] = '2';
            		break;

                case 'D':
                case 'E':
            	case 'F':
                    ch[i] = '3';
            		break;

                case 'G':
                case 'H':
            	case 'I':
                    ch[i] = '4';
            		break;

                case 'J':
                case 'K':
            	case 'L':
                    ch[i] = '5';
            		break;

                case 'M':
                case 'N':
            	case 'O':
                    ch[i] = '6';
            		break;

                case 'P':
                case 'Q':
            	case 'R':
            	case 'S':
                    ch[i] = '7';
            		break;

                case 'T':
                case 'U':
            	case 'V':
                    ch[i] = '8';
            		break;

                case 'W':
            	case 'X':
            	case 'Y':
            	case 'Z':
                    ch[i] = '9';
            		break;

            	default:
            		break;
            }
            printf("%s\n", ch);
    }
    return 0;
}

10931 Parity.c

#include <stdio.h>
#include <string.h>

int main()
{
    long int num;
    int count;
    int i, j, a[100];

    scanf("%ld", &num);

    while(num > 0)
    {
        count = 0;
        for (i = 0; num != 0; ++i)
        {
            a[i] = num % 2;
            num = num / 2;
            if (a[i] == 1) count++;
        }

        printf("The parity of ");

        for (j = i - 1; j >= 0; --j)
            printf("%d", a[j]);

        printf(" is %d (mod 2).\n", count);
        scanf("%ld", &num);
    }
    return 0;
}

10970 Big Chocolate.c

#include <stdio.h>

int main()
{
    int m, n, cut;

    while(scanf("%d %d", &m, &n) == 2)
    {
        cut = m - 1;
        cut += (n - 1) * m;
        printf("%d\n", cut);
    }
    return 0;
}

11150 Cola.c

#include <stdio.h>

int main()
{
    int n, count;

    while (scanf("%d", &n) == 1)
    {
        count = n + n / 2;

        printf("%d\n", count);
    }
    return 0;
}

11172 relational operators.c

#include <stdio.h>

int main()
{
    int a, b, i= 0, n;

    scanf("%d", &n);

    while (i < n)
    {
        scanf("%d %d", &a, &b);

        if (a > b) printf(">\n");
        else if (a < b) printf("<\n");
             else printf("=\n");
        i++;
    }
    return 0;
}

11185 Ternary.c

#include <stdio.h>
#include <string.h>

int main()
{
    long int num;
    int i, j, a[100];

    scanf("%ld", &num);

    while(num >= 0)
    {
        if (num == 0)
        {
            i = 1;
            a[0] = 0;
        }
        else
            for (i = 0; num != 0; ++i)
            {
                a[i] = num % 3;
                num = num / 3;
            }

        for (j = i - 1; j >= 0; --j)
            printf("%d", a[j]);

        printf("\n");
        scanf("%ld", &num);
    }
    return 0;
}