最大长方体问题

#include<stdio.h>

int rect[55][55][55];
int w,h,l;

int longest(int a[]){
    int i;
    int find=a[1];
    int b[55]={0,a[1],0};
for(i=2; i<=l; i++){
        b[i] = a[i];
        if(b[i-1]>0) b[i]+=b[i-1];
        if(find<b[i]) find=b[i];
    }
    return find;
}

int Rect(int a[55][55]) { 
    int i,j,k;
    int find=0;
    int b[55];
    int buf;
    for(i=1; i<=w; i++) {
        for(j=1; j<=l; j++)
            b[j]=0;
        for(j=i; j<=w; j++) {
            for(k=1; k<=l; k++) {
                b[k] += a[j][k];
            }
            buf=longest(b);