【HDOJ】3732 Ahui Writes Word

初看01背包，果断TLE。是因为n和C都比较大。但是vi和ci却很小，转化为多重背包。

#include <cstdio>
#include <cstring>

int map[15][15];
int dp[10005];
int n, C;

int max(int a, int b) {
    return a>b ? a:b;
}

void ZeroOnePack(int v, int c) {
    for (int i=C; i>=c; --i)
        dp[i] = max(dp[i-c]+v, dp[i]);
}

void CompeletePack(int v, int c) {
    for (int i=c; i<=C; ++i)
        dp[i] = max(dp[i-c]+v, dp[i]);
}

void MultiPack(int v, int c, int k) {
    if (c*k >= C) {
        CompeletePack(v, c);
        return ;
    }
    int r = 1;
    while (r < k) {
        ZeroOnePack(r*v, r*c);
        k = k - r;
        r <<= 1;
    }
    ZeroOnePack(k*v, k*c);
}

int main() {
    int v, c;
    char s[15];
    int i, j;

    while (scanf("%d %d", &n, &C) != EOF) {
        memset(map, 0, sizeof(map));
        memset(dp, 0, sizeof(dp));
        for (i=0; i<n; ++i) {
            scanf("%s %d %d", s, &v, &c);
            map[v][c]++;
        }
        for (i=1; i<=10; ++i) {
            for (j=0; j<=10; ++j) {
                if (map[i][j])
                    MultiPack(i, j, map[i][j]);
            }
        }
        printf("%d
", dp[C]);
    }

    return 0;
}