4
10
20

5
42
627

#include <stdio.h>
#include <string.h>
#define N 120
int c1[N+1], c2[N+1];
int main(){
    int i, j, k, n;
    for (i=0; i<=N; ++i){
        c1[i] = 1;
    }
    for (k=2; k<=N; ++k){
        memset(c2, 0, sizeof(c2));
        for (i=0; i<=N; ++i){
            for (j=i; j<=N; j+=k){
                c2[j] += c1[i];
            }
        }
        memcpy(c1, c2, sizeof(c2));
    }
    while (scanf("%d", &n) == 1){
        printf("%d\n", c1[n]);
    }
    return 0;
}

0
1
2
3
4
5

no
no
yes
no
no
no

#include <stdio.h>
int main(){
    int n, t;
    while (scanf("%d", &n) == 1){
        t = n&7;
        printf("%s\n", t==2 || t==6 ? "yes" : "no");
    }
    return 0;
}

2
3 5 7 15
6 4 10296 936 1287 792 1

105
10296

#include <stdio.h>
int gcd(int x, int y){
    if (y == 0){
        return x;
    }
    int i = x&1, j = y&1;
    return i ? j ? (x>y ? gcd(y, x-y) : gcd(x, y-x)) : gcd(x, y>>1): j ? gcd(x>>1, y) : gcd(x>>1, y>>1)<<1;
}
int lcm(int x, int y){
    return x/gcd(x, y)*y;
}
int main(){
    int z, n, t, r;
    scanf("%d", &z);
    while (z-- != 0){
        scanf("%d", &n);
        scanf("%d", &r);
        while (--n != 0){
            scanf("%d", &t);
            r = lcm(r, t);
        }
        printf("%d\n", r);
    }
    return 0;
}

1

10 1
20 3
30 4
0 0

Case 1: 2
Case 2: 4
Case 3: 5

#include <stdio.h>
int a2b2[101][101];
int ab[101][101];
int a[101];
int main(){
    int zz, z, n, m, i, j, b, r;
    for (i=1; i<=100; ++i){
        a[i] = i*i;
    }
    for (i=1; i<=100; ++i){
        for (j=1; j<=100; ++j){
            a2b2[i][j] = a[i]+a[j];
            ab[i][j] = i*j;
        }
    }
    b = 0;
    scanf("%d", &zz);
    while (zz-- != 0){
        if (b){
            printf("\n");
        }
        b = 1;
        z = 0;
        for (;;){
            scanf("%d %d", &n, &m);
            if (n==0 && m==0){
                break;
            }
            r = 0;
            for (i=1; i<n; ++i){
                for (j=i+1; j<n; ++j){
                    if ((a2b2[i][j]+m)%ab[i][j] == 0){
                        ++r;
                    }
                }
            }
            printf("Case %d: %d\n", ++z, r);
        }
    }
    return 0;
}

3 5
15 20
63923 99999

         3         5    Good Choice

        15        20    Bad Choice

     63923     99999    Good Choice

#include <stdio.h>
int gcd(int x, int y){
    if (y == 0){
        return x;
    }
    int i = x&1, j = y&1;
    return i ? j ? (x>y ? gcd(y, x-y) : gcd(x, y-x)) : gcd(x, y>>1) : j ? gcd(x>>1, y) : gcd(x>>1, y>>1)<<1;
}
int main(){
    int x, y;
    while (scanf("%d %d", &x, &y) == 2){
        printf("%10d%10d    %s\n\n", x, y, gcd(x, y)==1 ? "Good Choice" : "Bad Choice");
    }
    return 0;
}

24
39
0

6
3

#include <stdio.h>
int f(int n){
    if (n <= 9){
        return n;
    }
    int r = 0;
    while (n > 0){
        r += n%10;
        n /= 10;
    }
    return f(r);
}
int main(){
    char s[1025];
    int i, n;
    while (scanf("%s", s) == 1){
        n = 0;
        for (i=0; s[i]; ++i){
            n += s[i]-'0';
        }
        if (n == 0){
            break;
        }
        printf("%d\n", f(n));
    }
    return 0;
}

n e
- -----------
0 1
1 2
2 2.5
3 2.666666667
4 2.708333333

#include <stdio.h>
int main(){
    double sum;
    int n, i, l;
    printf("n e\n");
    printf("- -----------\n");
    printf("0 1\n");
    sum = 1;
    l = 1;
    for (n=1; n<=9; ++n){
        l *= n;
        sum += 1.0/l;
        if (n <= 2){
            printf("%d %g\n", n, sum);
        }
        else{
            printf("%d %.9lf\n", n, sum);
        }
    }
    return 0;
}

1 2
3 2 3 1
0

17
41

#include <stdio.h>
int main(){
    int n, t, l, r;
    while (scanf("%d", &n) == 1){
        if (n == 0){
            break;
        }
        r = 0;
        l = 0;
        while (n-- != 0){
            scanf("%d", &t);
            if (t > l){
                r += (t-l)*6;
            }
            else{
                r += (l-t)*4;
            }
            r += 5;
            l = t;
        }
        printf("%d\n", r);
    }
    return 0;
}

1 1 3
1 2 10
0 0 0

2
5

#include <stdio.h>
#include <string.h>
int main(){
    int b[7][7];
    int a[100];
    int n;
    int x, y, m, st, len;
    while (scanf("%d %d %d", &x, &y, &m) == 3){
        if (x==0 && y==0 && m==0){
            break;
        }
        a[1] = 1;
        a[2] = 1;
        memset(b, 0, sizeof(b));
        b[1][1] = 1;
        n = 3;
        for (;;){
            a[n] = (a[n-1]*x+a[n-2]*y)%7;
            if (b[a[n-1]][a[n]] != 0){
                break;
            }
            b[a[n-1]][a[n]] = n-1;
            ++n;
        }
        st = b[a[n-1]][a[n]];
        len = n-1-st;
        if (m < st){
            printf("%d\n", a[m]);
        }
        else{
            printf("%d\n", a[st+(m-st)%len]);
        }
    }
    return 0;
}

5
green
red
blue
red
red
3
pink
orange
pink
0

red
pink

#include <stdio.h>
#include <string.h>
#define N 390
const char C = 'a'-1;
struct bal_t{
    char color[16];
    int fre;
}bal[N+1];
int hash(char s[]){
    int r = 0;
    char *p = s;
    char c;
    while ((c=*p++) != '\0'){
        r += c-C;
    }
    return r;
}
int main(){
    char s[16];
    int n, i, t, max, max_i;
    while (scanf("%d", &n) == 1){
        if (n == 0){
            break;
        }
        for (i=0; i<=N; ++i){
            bal[i].fre = 0;
        }
        while (n-- != 0){
            scanf("%s", s);
            t = hash(s);
            if (bal[t].fre != 0){
                ++bal[t].fre;
            }
            else{
                strcpy(bal[t].color, s);
                bal[t].fre = 1;
            }
        }
        max = 0;
        for (i=0; i<=N; ++i){
            if (bal[i].fre > max){
                max = bal[i].fre;
                max_i = i;
            }
        }
        printf("%s\n", bal[max_i].color);
    }
    return 0;
}