The best matching of bipartite graph - KM algorithm

Calculate the sum of N numbers in an N*N matrix, the value is the largest, and only one non-original code source forum
is selected for each row and column

About the KM algorithm

#include<iostream> //O(n^3)的KM
#include<cstring> 
using namespace std;
const int maxn=101;
const int inf= 10000000;
int tc;
int g[maxn][maxn], lx[maxn], ly[maxn], vx[maxn], vy[maxn], mat[maxn],slack[maxn];
int n;
bool find(int u) {
    vx[u] = 1;
    for(int v=1; v<=n; v++) {
        if(!vy[v] && lx[u] + ly[v] == g[u][v]) {
            vy[v] = 1;
            if(mat[v] == -1 || find(mat[v])) {
                mat[v] = u;
                return true;
            }
        } else if(lx[u]+ly[v]>g[u][v])
            slack[v]=min(slack[v],lx[u]+ly[v]-g[u][v]);
    }
    return false;
}

void km() {
    int d, sum;
    memset(lx, 0, sizeof(lx));
    memset(ly, 0, sizeof(ly));
    memset(mat, -1, sizeof(mat));
    for(int i=1; i<=n; i++) {
        for(int j=1; j<=n; j++) {
            lx[i]=max(lx[i],g[i][j]);
        }
    }
    for(int k=1; k<=n; k++) {
        while(1) {
            memset(vx, 0, sizeof(vx));
            memset(vy, 0, sizeof(vy));
            for(int i=1; i<=n; i++)
                slack[i]=inf;

            if(find(k))
                break;
            d = inf;
            for(int i=1; i<=n; i++) {
                if(!vy[i]) {
                    d=min(d,slack[i]);
                }
            }
            for(int i=1; i<=n; i++) {
                if(vx[i])
                    lx[i] -= d;
                if(vy[i])
                    ly[i] += d;

            }
        }
    }
    sum = 0;
    for(int i=1; i<=n; i++)
        sum += lx[i] + ly[i];
    printf("%d\n", sum);
}

int main() {
    while(scanf("%d",&n)&& n) {
        for(int i=1; i<=n; i++) {
            for(int j=1; j<=n; j++) {
                scanf("%d",&g[i][j]);
            }
        }
        km();
    }
    return 0;
}